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STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 
DIVISION  OF  THE 

STATE  GEOLOGICAL  SURVEY 

FRANK  W.  DEWOLF.  ChUf 
EXTRACT  FROM  BULLETIN  No.  43 


GEOLOGY  AND  MINERAL  RESOURCES  OF  THE 
MORRIS  QUADRANGLE 


BY 


HAROLD  E.  CULVER 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1922 


Return  this  book  on  or  before  the 
Latest  Date  stamped  below. 

University  of  Illinois  Library 


l.lr.l  — H41 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 
DIVISION  OF  THE 

STATE  GEOLOGICAL  SURVEY 

FRANK  W.  DEWOLF,  Chief 

EXTRACT  FROM  BULLETIN  No.  43 


GEOLOGY  AND  MINERAL  RESOURCES  OF  THE 
MORRIS  QUADRANGLE 


BY 


HAROLD  E.  CULVER 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1922 


AT  llt^^^'S  LiPn. 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

DIVISION  OF  THE 

STATE  GEOLOGICAL  SURVEY 

Frank  W.  DeWolf,  Chief 


Committee  of  the  Board  of  Natural  Resources 
and  Conservation 

A.  M.  Shelton,   Chairman 

Director  of  Registration  and  Education 

Kendric  C.  Babcock 

Representing  the  President  of  the  Uni- 
versity of  Illinois 

RoLi.iN  D.  Salisbury 
Geologist 


GEOLOGY  AND  MINERAL  RESOURCES  OF  THE 
MORRIS  QUADRANGLE 

By  Harold  E.  Culver 


OUTLINE 

PAGE 

Chapter  I. — Introduction 9 

Position 9 

General  relations 9 

Acknowledgments 9 

Chapter  II. — Topography 10 

Relief 10 

Drainage 11 

Culture 12 

Chapter  III. — Descriptive  geology 13 

Cambrian  system 13 

Ordovician  system 16 

Lower  Ordovician  series 16 

Middle  Ordovician  series 17 

St.  Peter  sandstone 18 

Platteville  limestone 21 

Galena  dolomite 23 

Upper  Ordovician  series 30 

Maquoketa  formation 30 

Pennsylvanian  system 38 

Pottsville  formation 43 

Correlation 44 

Carbondale  formation 49 

Pleistocene  system 57 

Pre-Wisconsin  drift 57 

Wisconsin  drift 58 

Bloomington  deposits 58 

Lacustrine  clays 58 

Marseilles  deposits 59 

Minooka  deposits 63 

Fluvial  and  lacustrine  deposits 64 

Recent  deposits 71 

Chapter  IV. — Structural  geology 75 

Chapter  V. — Historical  geology 79 

Cambrian  period 79 

Ordovician  period 79 

Pennsylvanian  period 81 

Mesozoic  and  Cenozoic  eras 83 

Pleistocene  period 83 

Marseilles  stage 84 

Minooka  stage 87 

Lake  Morris  sub-stage 88 

Cryder  Lake  sub-stage 90 

Later  history  of  Illinois  valley 92 

5 


OUTLINE  —  Continued 

PAGE 

Chapter  VI. — Economic  geology 95 

Coal 95 

General  relations 95 

Pottsville  coals 96 

Carbondale  coals 96 

No.  2  coal 96 

Physical  character 97 

Chemical  composition 97 

Coal  beds  above  No.  2 101 

Coal  mining 102 

Clay  and  shale 104 

Ordovician  shale 104 

Pennsylvanian  shale 104 

Pleistocene  clay 106 

Stone 107 

Sand  and  gravel 108 

Water 109 

Soils Ill 

Oil 113 


ILLUSTRATIONS 

PLATE 

II.     Surficial  geology  and  rock  outcrops  of  the  Morris  quadrangle In  pocket 

III.     Economic,  structural,  and  areal  geology  of  the  Morris  quadrangle In  pocket 

IIIA.  Map  of  Morris  Basin  showing  major  physiographic  features 86 

FIGURE 

12.  Index  map  of  Illinois,  showing  the  location  of  the  Morris  quadrangle 8 

13.  The  head  of  the  Illinois  from  the  west  side  of  Minooka  ridge 10 

14.  Generalized  columnar  section  of  the  rocks  of  the  Morris  quadrangle 14 

15.  Quarry  in  Galena  dolomite  at  Central,  Kendall  County 26 

16.  Profile  and  structure  section  across  Morris  Basin 27 

17.  Underground  relations  in  southwestern  Saratoga  Township,  Grundy  County.  ...  29 

18.  Aux  Sable  Creek  at  Shurtliffe  Bridge,  Kendall  County 31 

19.  Structure  section  across  Kankakee  River,  near  Lorenzo 36 

20.  Carbondale  sandstone,  showing  characteristic  thin  bedding  and  resistant  lenses..  39 

21.  Lenticular  concretions  in  Pennsylvanian  beds  along  Mazon  River 41 

22.  Typical  sandy  shale  of  the  Carbondale  formation 42 

23.  Spherical  concretion  in  sandstone  on  Aux  Sable  Creek 46 

24.  Pennsylvanian  beds  in  the  clay  pit  at  the  west  end  of  Goose  Lake 47 

25.  Exposures  of  Carbondale  beds  along  Mazon  Ri\'er  near  Tieders  Ford 48 

26.  Typical  exposures  of  Carbondale  strata  on  Mazon  River 49 

27.  Waupecan  sandstone  and  underlying  beds  on  Waupecan  Creek 50 

28.  Exposure  showing  beds  below  Waupecan  sandstone 51 

29.  Fissile  shale  showing  calcareous  phase  with  cone-in-cone  structure 53 

30.  Uneven  contact  of  Waupecan  sandstone  with  underlying  shales 54 

31.  "Millstone"  concretions  of  Waupecan  sandstone 55 

32.  Sketch  of  outcrop  of  lake  clays  showing  overlying  till 59 

33.  Map  of  Morris  quadrangle  showing  contours  on  bed-rock  surface 61 

34.  Dune  near  east  end  of  sand  ridge 65 

35.  Gravel  pit  in  N.  E.  }4  sec.  33,  Goose  Lake  Township 66 

6 


ILLUSTRATIONS  —  Continued 

FIGURE  PAGE 

36.  View  showing  the  topographic  relation  between  the  present   Illinois  floodplain 

and  the  earlier  gravel  deposits 67 

37.  Terrace  gravels  over  till  along  Nettle  Creek  in  Saratoga  Township 70 

38.  Near  view  of  terrace  gravel  showing  relation  to  till 71 

39.  Gravel  deposit  in  sec.  21,  Wauponsee  Township 91 

40.  Graphic  sections  of  No.  2  seam,  Morris  quadrangle 100 

41.  Refuse  dump  of  shale  and  impure  coal  from  mine  near  Coal  City 102 

42.  Typical  surface  equipment  of  a  local  coal  mine  at  Morris 103 

43.  View  of  small  strip  pit  northeast  of  Morris 104 


TABLES 

3.  Tabulated  data  on  the  St.  Peter  sandstone  for  Morris  Quadrangle 19 

4.  Tabulated  data  on  the  Platteville  limestone 22 

5.  Logs  of  wells  near  Lorenzo,  Will  County 37 

6.  Proximate  analyses  of  No.  2  coal  from  Morris  Quadrangle. 98 


GEOLOGY    OF    MORRIS   QUADRANGLE 


Fig.   12.     Index  map  of  Illinois,  showing  the  location  of  the  Morris  Quadrangle. 
The  stippled  boundary  outlines  the  Illinois  coal  field. 


CHAPTER  I— INTRODUCTION 

Position 

The  region  examined  in  this  investigation  Hes  along  IlHnois  River  in  the 
vicinity  of  Morris  (fig.  12).  It  comprises  approximately  half  of  Grundy 
County  and  a  three-mile  strip  nearly  across  the  southern  part  of  Kendall 
County.  The  area  has  a  width  of  15  minutes  of  longitude,  lying  between 
meridians  88°  15'  and  88°30'  west  longitude,  and  a  length  of  15  minutes  of 
latitude,  lying  between  parallels  41°  15'  and  41°30'  north  latitude.  The  quad- 
rangle includes  224.41  square  miles  within  its  boundaries,  which  disregard 
section,  township,  and  county  lines,  being  drawn  in  accordance  with  a  plan 
for  the  systematic  mapping  of  all  the  land  in  the  United  States. 

General  Relations 

While  at  present  primarily  of  importance  for  its  agriculture,  this  region 
is  one  that  will  be  benefited  by  the  proposed  Lakes-to-Gulf  waterway,  which, 
in  addition  to  its  stimulating  efifect  upon  farming,  may  make  possible  a  greater 
development  of  its  other  industries.  In  earlier  days  before  the  utilization  of 
the  thick  coal  beds  in  the  southern  part  of  the  State,  coal  mining  was  an 
important  industry  within  the  Morris  quadrangle,  although  in  1920  there 
is  but  one  shipping  mine  in  operation. 

Geologically  the  quadrangle  is  of  interest  because  it  includes  a  portion 
of  the  present  boundary  of  the  Eastern  Interior  Coal  Basin,  which  com- 
prises the  coal  lands  of  all  of  Illinois,  Indiana,  and  western  Kentucky.  Within 
the  "Coal  Measures"  here  exposed  are  found  the  famous  fossil  beds  of 
Mazon  River,  from  which  collections  of  almost  perfectly  preserved  remains 
of  plants  and  animals  have  been  taken  to  many  parts  of  the  world.  In  addi- 
tion, the  Pleistocene  or  Glacial  history  of  the  region  is  of  special  interest 
since  this  portion  of  the  valley  of  IlHnois  River  was  the  site  of  an  interest- 
ing series  of  drainage  changes  which  were  closely  related  to  the  development 
of  glacial  Lake  Chicago  and  its  outlet  river. 

Acknowledgments 

In  the  gathering  of  data  for  this  investigation  the  writer  has  enjoyed  the 
courteous  cooperation  of  a  large  number  of  ])e()])le  living  within  the  quad- 
rangle. He  is  especially  indebted  to  the  well  drillers  of  the  region  for  well 
logs,  and  to  the  mine  operators  for  underground  data. 

Bulletin  10  of  the  Cooperative  Mining  Investigations'  has  been  very 
helpful  and  has  been  freely  drawn  upon,  as  have  some  of  the  unpublished 
data  gathered  by  former  members  of  the  Survey  staff. 

iCady.  G.  H.,  Coal  resources  of  District  I:    III.  Coal  Mining  Investigations  Bull.  10,  1915. 


10 


GEOLOGY   OF    MORRIS   QUADRANGLE 


Credit  is  due  Mr.  Frank  Collins  Baker,  who  kindly  determined  the 
Pleistocene  fossils,  and  offered  suggestions  as  to  the  correlation  of  the  enclos- 
ing deposits. 

The  writer  wishes  to  express  his  appreciation  of  help  given  by  the  sev- 
eral members  of  the  Survey  staff,  particularly  Professor  T.  E.  Savage,  who 
determined  the  Paleozoic  fossils,  and  Professor  Morris  M.  Leighton  with 
whom  the  Pleistocene  study  was  initiated,  and  who  has  given  the  benefit  of 
his  experience  in  glacial  investigations  in  this  region,  both  by  field  assistance 
and  by  criticism  of  the  Pleistocene  chapters. 

TOPOGRAPHY 

The  quadrangle  includes  the  central  part  of  the  so-called  Morris  Basin. 
To  the  traveler  the  basin-like  shape  is  not  readily  apparent  because  of  its 


Fig.  13.     The  head  of  the  IlHnois  from  the  west  side  of  Minooka  Ridge.     The  Desplaines  is  seen  in  the 
middle  distance,  with  the  Kankakee  coming  in  from  the  south 

extreme  shallowness,  but  is  evident  from  the  topographic  map,  and  is  empha- 
sized by  the  arrangement  of  stream  courses. 


Relief 

The  relief  of  the  region  as  a  whole  is  slight,  there  being  less  than  200  feet 
of  difference  between  the  highest  and  lowest  points  in  the  quadrangle.  The 
greatest  local  relief  is  found  at  Dresden  Heights,  where  the  Illinois  has  cut  a 
sharp  bank  120  feet  high  in  the  glacial  deposits  of  Minooka  Ridge  (fig.  13). 
The  other  features  of  pronounced  relief  are  a  short  ridge  in  section  13  of 
Saratoga  Township,  the  cemetery  ridge  west  of  Morris,  and  the  sharply 
incised  valleys  of  some  of  the  streams  in  the  southwest  part  of  the  quad- 


DRAINAGE  11 

rangle.  Elsewhere  the  topography  is  of  monotonous  smoothness,  the  greater 
part  of  the  area  lying  between  540  and  620  feet  above  sea  level. 

Notwithstanding  this  notable  lack  of  relief,  certain  topographic  features 
of  the  region  are  not  without  interest.  For  example,  Ridge  Road,  leading 
northeast  from  Morris,  runs  along  the  upper  edge  of  a  prominent  embank- 
ment, a  topographic  form  obviously  unrelated  to  the  flat  adjoining  on  the 
north.  Similarly,  the  irregular  depression  of  Goose  Lake,  the  flat  knolls  to 
the  north,  and  the  collection  of  dunes  known  as  Sand  Ridge  to  the  south  are 
features  suggestive  of  interesting  relations. 

It  is  evident  to  the  careful  observer  that  the  topography  of  pre-glacial 
time  has  been  almost  obliterated  by  the  work  of  later  agents.  Furthermore, 
it  becomes  apparent  upon  inspection  of  the  region  that  the  general  smooth- 
ness is  largely  due  to  the  work  of  ice,  while  the  relation  of  the  local  relief 
features  to  the  valley  of  the  Illinois  strongly  suggests  their  origin  in  later 
stream  action. 

Drainage 

The  master  stream  of  the  quadrangle  is  the  Illinois,  which  heads  within 
half  a  mile  of  the  eastern  boundary  of  the  quadrangle  at  the  junction  of  the 
Des  Plaines  and  Kankakee  rivers.  The  latter  stream  has  a  northerly  course 
above  that  point  and  enters  the  quadrangle  about  two  miles  to  the  south  near 
the  point  where  it  is  crossed  by  the  County  Line  Bridge. 

The  Illinois  flows  a  little  south  of  west  at  a  velocity  which  varies  from 
3/2  to  3  miles  an  hour.  From  data  gathered  at  the  Federal  gaging  station  at 
Elgin,  Joliet,  and  Eastern  Railway  bridge  about  seven  miles  east  of  Morris,^ 
the  variation  in  measured  volume  amounts  to  57,000  second  feet,  the  extremes 
of  observed  flow  being  7,000  and  64,000  second  feet.  With  these  changes, 
the  water  level  fluctuates  as  much  as  25  feet,  the  lowest  recorded  stage  being 
486  feet  and  the  highest  511  feet  above  sea  level.  The  flood  plain  shows 
great  irregularity  of  outline  but  has  an  average  width  of  about  a  mile.  Nu- 
merous sloughs  and  lakes  on  the  flood  plain  indicate  relatively  recent 
changes  in  the  channel.  Another  feature  worthy  of  notice  is  the  abundance 
of  elongate  low-water  islands  of  silt  which  characterize  this  portion  of  the 
Illinois  as  a  depositing  stream.  By  way  of  contrast,  it  is  of  interest  to  note 
that  the  Kankakee  in  its  lower  course  is  eroding  its  channel  in  resistant 
sandstone  and  limestone  beds.  In  lesser  degree  this  is  characteristic  of  the 
Des  Plaines  also. 

No  tributaries  of  consequence  enter  the  Des  Plaines  or  the  Kankakee 
within  the  quadrangle.  The  Illinois,  however,  has  four  prominent  tributaries 
and  several  small  ones.  The  two  largest,  Mazon  River  on  the  south  and  Aux 
Sable  Creek  on  the  north,  drain  more  than  three-quarters  of  the  area.  From 
the  northwest  comes  Nettle  Creek,  a  stream  of  two  branches  but  no  well 


2Water  Resources  of  Illinois:    Rivers  and  Lakes  Commission,  p.  34,  1914. 


12  GEOLOGY    OF    MORRIS    QUADRANGLE 

developed  tributary  system.  From  the  southwest  flow  Waupecan  Creek  and 
Bills  Run,  the  latter  of  recent  development  without  tributaries  or  branches, 
the  former  comparable  in  character  with  Nettle  Creek  on  the  north. 

Inspection  of  the  topographic  map  of  the  region  suggests  plainly  a  rela- 
tion between  the  courses  of  the  streams  and  the  early  history  of  Morris 
Basin.  In  the  case  of  every  stream  draining  the  western  half  of  the  quad- 
rangle the  course  shows  a  more  or  less  distinct  difference  in  trend  in  the 
upper  and  lower  portions.  This  change  in  trend  occurs  at  about  the  level 
of  the  earliest  lake  of  which  we  have  record  in  this  depression. 

The  arrangement  of  stream  courses  has  been  referred  to  as  emphasizing 
the  shape  of  the  Morris  Basin.  This  type  of  drainage,  characterized  by  the 
control  of  stream  courses  by  the  original  slope  of  the  land  surface  is  known 
as  consequent,  and  marks  this  as  a  region  just  starting  on  a  cycle  of  erosion. 

Culture 

This  district  exhibits  rural  settlement  rather  than  urban.  IMorris,  county 
seat  of  Grundy,  has  a  population  of  about  5,000 ;  Coal  City,  including  the  old 
mining  villages  of  Eileen,  Carbon  Hill,  and  Diamond,  has  approximately 
3,000  inhabitants.    Lisbon  and  ]\Iinooka  have  a  few  hundred  each. 

Nearly  all  the  land  is  under  cultivation,  aside  from  the  small  undrained 
areas  along  the  Illinois  and  the  forested  tracts.  The  v^oodlands  are  restricted 
to  stream  courses  and  sand  areas,  and,  as  shown  by  the  topographic  survey 
of  1915,  comprise  less  than  five  per  cent  of  the  total  area  of  the  quadrangle. 
That  portion  of  Grundy  County  included  in  the  quadrangle  has  less  than  ten 
square  miles  of  wooded  land,  while  the  Kendall  County  part  has  less  than 
one  square  mile.  The  soil  is  for  the  most  part  fertile,  and  good  crops  are 
the  rule.  The  production  of  certain  areas  has  been  increased  by  the  addition 
of  limestone  and  phosphate. 

The  region  is  well  supplied  with  roadways,  which  follow  the  section 
lines  in  the  main.  Along  the  Illinois  valley,  however,  the  roads  are  parallel 
to  its  trend.  There  are  many  miles  of  hard  surfaced  roads,  so  that  during 
most  of  the  year  a  large  part  of  the  district  is  accessible  by  automobile.  The 
mileage  of  paved  road  is  being  greatly  increased  at  present  with  the  comple- 
tion of  the  Chicago-Illinois  Valley  highway  and  other  main  thoroughfares. 

Adequate  rail  service  is  furnished  by  the  lines  between  Chicago  and  the 
southwest.  The  main  line  of  the  Chicago,  Rock  Island  and  Pacific  Railroad 
passes  through  Morris  and  Minooka,  that  of  the  Atchison,  Topeka  and 
Santa  Fe  Railway  passes  through  Coal  City,  while  a  branch  of  the  Cleveland, 
Cincinnati,  Chicago  and  St.  Louis  Railroad  crosses  the  extreme  southwestern 
part  through  Wauponsee.  The  eastern  part  of  the  quadrangle  is  also  served 
by  the  Elgin,  Joliet  and  Eastern  Railway.  Additional  service  is  provided  by 
two  electric  lines,  the  Chicago,  Ottawa  and  Peoria  Railway,  and  the  Illinois 
Valley  and  Fox  River  Union. 


CHAPTER  III— DESCRIPTIVE  GEOLOGY 

Solid  rock  of  sedimentar}^  origin  underlies  the  loose  surficial  material  in 
all  parts  of  the  quadrangle  at  depths  ranging  from  a  few  inches  to  more  than 
120  feet.  In  the  valleys  of  the  larger  streams,  and  rarely  elsewhere,  are 
scattered  exposures  of  limestone,  shale,  or  sandstone,  which,  as  shown  by 
drilling  operations,  are  continuous  under  wide  areas  to  a  depth  of  more  than 
2,000  feet.  Numerous  borings  of  not  more  than  a  few  hundred  feet  have 
been  made  in  search  of  water,  coal,  oil,  or  gas.  There  are  also  a  few  deeper 
wells,  of  which  that  on  the  farm  of  Mr.  Abe  Hoge,  Sr.,  located  in  NW,  54 
NW.  y^  sec.  25,  T.  34  N.,  R.  6  E.,  reaching  1,921  feet,  is  perhaps  the 
deepest. 

From  the  logs  of  these  holes,  together  with  field  studies  of  the  outcrops 
in  this  and  adjoining  quadrangles,  the  geologic  column  showing  the  sequence 
and  thickness  of  the  strata  for  this  region  has  been  constructed.  The  rocks 
belong  to  a  group  of  strata  known  as  the  Paleozoic,  which  is  conveniently 
subdivided  into  seven  systems,  two  of  which  are  known  to  outcrop  in  the 
Morris  quadrangle,  one  other  being  known  from  drilling. 

The  generalized  geologic  section  (fig.  14)  is  typical  of  the  quadrangle, 
but  not  exactly  duplicated  in  any  one  boring.  The  reason  for  dissimilarity 
in  diflferent  borings  will  become  clear  upon  inspection  of  the  areal  map 
(PI.  III).  A  well  near  Lisbon  will  enter  bed  rock  of  Middle  Ordovician 
age,  one  near  Minooka  will  start  in  Upper  Ordovician  strata,  while  one  near 
Coal  City  will  pass  first  through  Pennsylvanian  beds,  then  through  Upper, 
Middle,  and  Lower  Ordovician  beds,  and  since  the  thickness  of  these  forma- 
tions varies  from  place  to  place,  none  of  these  wells  will  encounter  a  section 
exactly  like  that  given  above. 

Cambrian  System 

The  Cambrian  System,  which  includes  the  oldest  rocks  encountered  in 
this  region,  lies  more  than  1,000  feet  beneath  the  surface  and  has  been 
reached  by  but  few  wells  within  the  Morris  quadrangle.  Consequently  it  is 
little  known  and  has  no  economic  importance  since  it  furnishes  only  water, 
which,  though  abundant,  is  of  an  inferior  grade.  At  least  two  wells  have 
been  drilled  into  the  Cambrian,  the  first  in  1875,  on  section  25,  Nettle  Creek 
Township  (T.  34  N.,  R.  6  E.),  the  Hoge  well  mentioned  earlier,  and  the 
second  in  1886  in  the  village  of  Minooka.  No  record  of  the  latter  is  avail- 
able, but  that  of  the  former  makes  possible  certain  conclusions  regarding 
these  deeply  buried  strata.  The  Hoge  well  encountered  beds  believed  to  be 
of  Cambrian  age  at  1,200  feet  and  was  continued  for  about  700  feet  more. 
The  complete  log,  with  geologic  interpretations,  is  given  below.     In  both 

13 


14 


GEOLOGY   OF    MORRIS   QUADRANGLE 


Scale  in  feet 


200 


400 


600 


800 


1000 


1200 


1400 


1600 


-1800 


mM 


T~T 


Morris  No.  2  coal 


rCi 


Maquoketa 


Galena 
and 

Platteville 


St.  Peter 


!    '.    I    I 


I       I 


"TTT 


T^T- 


T-^T- 


Shakopee 


New  Richmond 


Oneota 


Croixian 


S 


S 


1 '^ 


LEGEND 


Till 


Clay 


-^ 


Shale 


Sandy  Shale 


Sandstone 

— n 


Limestone 


Dolomite 


Coal 


Fig.  14.  Generalized  columnar  section  of  the  rocks  of  the  Morris  Quadrangle 


CAMBRIAN    SYSTEM  IS 

wells  an  abundant  flow  of  water  under  high  pressure  was  obtained,  but  that 
of  the  first  well  ceased  after  many  years,  probably  on  account  of  clogging  of 
the  well  by  caving  matter. 

Log" of  an  artesian  well  on  the  farm  of  Abe  JJoge,  NW.  I4  NW.  K  sec.  25,  T.  34  A'.,  7^.  6  E. 

(Well  drilled  in  1875)                               Thickness  Depth 

Description  of  strata  Feet  Feel 
Pleistocene  and  Recent 

Soil 50  50 

Pennsylvanian 

Soapstone 8  58 

Sandstone;  soapstone 70  128 

Ordovician 

Galena- Platte\'ille 

Limestone 200  328 

Shale 2  330 

St.  Peter 

Sandstone 200  530 

"Cement"  and  shale 8  538 

Sandstone 60  598 

Prairie  du  Chien 

Limestone,  white 1  '^5  /  83 

Sandstone,  white 93  8/6 

Limestone,  white 326  1 202 

Cambrian  (?) 

Sandstone,  red 166  1368 

Limestone,  gray -^0  1398 

Sandstone 317  1715 

Limestone,  gray -13  1 758 

Sandstone.^ 163.5  1921.5 

a  Log  kindly  furnished  by  Mr.  Abe  Hoge,  Sr..  of  Morri.s. 

The  Cambrian  system  has  been  penetrated  east  of  the  quadrangle  near 
Minooka,  west  of  the  quadrangle  near  Marseilles,  and  at  Streator.  Com- 
parison of  these  logs  with  those  from  Ottawa,  Joliet,  Lockport,  Aurora, 
Batavia,  and  Argo,  suggests  that  the  Cambrian  of  the  Morris  region  may  be 
subdivided  into  three  members,  an  upper  sandstone  about  200  feet  thick, 
a  middle  member  comprising  shales  and  sandstones  with  thinner  interbedded 
limestones  about  300  feet  thick,  and  a  lower  sandstone  more  than  200  feet 
thick. 

The  difficulty  of  recognizing  the  base  of  the  overlying  Lower  Ordovician 
rocks  introduces  an  element  of  uncertainty  in  the  conclusions  regarding  the 
Cambrian.  However,  the  data  froiu  the  Hoge  boring  accord  well  with  the 
succession  in  other  parts  of  Illinois,  as  well  as  generally  throughout  the 
Upper  Mississippi  basin.  The  naiiie  "Potsdam,"  formerly  applied  to  this 
whole  series  of  beds  and  still  in  common  use,  should  be  dropped,  and  Croixan 
substituted. 


16  GEOLOGY   OF    MORRIS    QUADRANGLE 

On  the  basis  of  the  above  correlation,  the  Cambrian  has  a  general  south- 
easterly dip  of  about  14  feet  to  the  mile. 

Ordovician  System 

Rocks  of  Ordovician  age  underlie  all  of  the  quadrangle.  North  of  the 
"Coal  Measures"  area  all  outcropping  beds  belong  to  this  system,  which  else- 
where is  found  below  the  Pennsylvanian.  The  same  general  relations  obtain 
west  of  the  quadrangle  as  far  as  the  La  Salle  anticline.  To  the  east,  how- 
ever, these  strata  pass  beneath  Silurian  beds  which  outcrop  prominently  near 
Joliet. 

The  system  is  subdivided  into  three  series :  the  Lower  Ordovician,  com- 
prising the  Prairie  du  Chien ;  the  Middle  Ordovician,  including  the  St.  Peter 
sandstone,  the  Platteville  limestone,  and  the  Galena  dolomite ;  and  the  Upper 
Ordovician,  here  represented  by  the  Maquoketa  formation.  The  greatest 
measured  thickness  of  Ordovician  in  the  Morris  quadrangle  is  1,212  feet  at 
Coal  City,  but  since  the  full  thickness  of  Maquoketa  is  not  there  present,  and 
since  the  Cambrian  rocks  were  not  penetrated,  the  maximum  thickness  is 
probably  between  1,300  and  1,400  feet. 

LOWER   ORDOVICIAN   SERIES 

The  Lower  Ordovician  series,  formerly  known  as  the  Lower  Magnesian^ 
and  later  renamed  the  Prairie  du  Chien*,  comprises  three  formations,  to  which 
in  ascending  order,  the  names  Oneota,  New  Richmond,  and  Shakopee  have 
been  given.  With  the  exception  of  the  uppermost  beds  of  the  series,  these 
strata  are  but  little  better  known  than  those  of  Cambrian  age,  since  they  are 
seldom  reached  by  the  drill.  There  are  only  four  available  records  from  the 
Morris  quadrangle  although  there  are  as  many  more  from  contiguous  areas. 
Comparison  of  these  logs  shows  the  presence  in  this  area  of  representatives 
of  the  three  major  divisions  of  the  group  as  listed  above. 

The  lowest  formation,  the  Oneota,  is  usually  logged  as  white  limestone, 
although  it  is  dolomite.  It  is  326  feet  thick  in  the  Hoge  well  and  more  than 
346  feet  at  Coal  City  where  it  is  reported  to  include  more  than  150  feet  of 
sandstone  in  the  lower  middle  portion. 

The  next  formation  above  is  the  New  Richmond  sandstone.  Drill  cut- 
tings of  this  rock  show  it  to  be  in  most  places  clean  white  standstone  similar 
to  the  well-known  St.  Peter  formation  with  which  it  has  been  confused  not 
infrequently  in  drilling  operations.  It  is  separated  from  the  St.  Peter,  how- 
ever, by  more  than  100  feet  of  dolomite,  and  hence  can  be  distinguished  usu- 


»Owen.  D.  D.,  Ex.  Doc.  239,  26th  Cong.  1st  Sess..  p.  17,  1840. 

♦Grant.  U.  S.,  and  Burchard,  E.  F.,  U.  S.  Geol.  Survey  Geol.  Atlas,  Lancaster-Mineral  Point  folio   (No 
US),   1907. 


ORDOVICIAN    SYSTEM  17 

ally  by  position.  Careful  comparison  of  the  sand  grains  will  also  in  most 
cases  make  the  distinction  possible  as  the  grains  of  the  New  Richmond  are 
somewhat  larger.  xAlthough  in  the  records  for  this  quadrangle  this  is  a  pure 
sandstone  formation,  the  predominance  of  limestone  recorded  in  the  log  of 
the  Peddicord  well  north  of  Marseilles  suggests  the  probability  that  inter- 
bedded  limestones  exist  in  the  New  Richmond  formation  in  places.  This 
accords  with  its  character  in  the  vicinity  of  La  Salle.'  The  formation  is  113 
feet  thick  at  Coal  City,  and  93  feet  in  the  Hoge  well. 

The  uppermost  formation  of  the  Prairie  du  Chien  series  outcrops  in 
various  parts  of  the  State,  and  hence  is  better  known  than  the  underlying 
strata.  It  is  dolomite  of  light  color,  usually  gray  or  bufif,  mainly  fine  grained 
but  showing  coarse  granular  texture  and  marked  porosity  in  places.  This 
coarse  phase  together  with  the  thin  interbedded  sandstones,  account  for  the 
formation  being  sometimes  incorrectly  reported  in  drill  logs  as  sandstone. 

In  the  Hoge  w^ell  it  is  recorded  as  white  limestone,  185  feet  thick.  The 
Morris  city  well  shows  it  to  be  light-gray  dolomite,  rather  dense  in  texture, 
thickness  not  known.  Four  miles  to  the  southeast  a  well  on  the  John  Holder- 
man  farm  records  27  feet  in  limestone  belonging  to  this  fo-rmation,  and  at 
Coal  City  the  total  thickness  of  this  stratum,  described  as  sandy  limestone, 
is  125  feet. 

Just  east  of  Coal  City,  at  Braidwood,  it  is  reported  as  a  formation  com- 
posed of  white  limestone  and  gray  shale  which  was  penetrated  for  a  depth 
of  45  feet.  More  clastic  material,  both  shale  and  sandstone,  appear  in  this 
zone  as  it  is  traced  northeastward,  as  much  as  50  feet  of  shale  appearing  at 
the  top  in  wells  near  Joliet. 

MIDDLE  ORDOVICIAN    SERIES 

This  series,  like  the  foregoing,  has  three  formations  which  underlie  most 
if  not  all  of  the  Morris  quadrangle.  The  lowest  formation,  the  well-known 
St.  Peter  sandstone,  is  recognized  readily  by  drillers  and  serv^es  as  a  datum 
plane  from  which  reasonably  accurate  stratigraphic  measurements  may  be 
made  on  well  logs.  The  other  two  formations,  the  Platteville  limestone  and 
the  Galena  dolomite,  are  indistinguishable  in  this  region  since  only  the  latter 
outcrops  and  no  criteria  for  the  recognition  of  the  contact  of  the  two  in 
drill  logs  have  been  developed.  This  portion  of  the  series  is  therefore 
referred  to  as  the  Galena-Plattevillc  formation  in  this  report.  The  measured 
thickness  for  this  series  in  the  quadrangle  ranges  from  470  feet  in  the  Hoge 
well  to  581  feet  in  the  Morris  city  well  No.  2.  Figures  for  the  latter  may  be 
slightly  in  error  but  tlieir  approximate  accuracy  is  indicated  l)y  a  recorded 
thickness  of  550  feet  in  the  Coal  Citv  well. 


5Cady,  G.  H.,  Geology  and  mineral  resources  of  the  Hennepin  and  La  Salle  quadrangles:    111.  State 
Geol.  Survey  Bull.  37,  p.  3S,  1919. 


18  GEOLOGY   OF    MORRIS   QUADRANGLE 


ST.    PETER    SANDSTONE 


Outcrops  of  this  formation  west  of  the  quadrangle  in  La  Salle  County 
show  it  to  be  sandstone  of  unusual  purity.  It  is  composed  of  well-rounded 
quartz  grains  which  are  in  places  but  slightly  cemented  and  in  places  firmly 
held  together.  Drill  cuttings  are  nearly  always  composed  of  loose  grains. 
While  the  upper  and  lower  portions  are  stained  to  a  greater  or  less  degree 
and  hence  appear  yellow  or  brown,  black  or  blue,  the  formation  as  a  whole 
is  almost  snow-white.  This,  taken  with  the  rather  uniformly  small  size  of 
grain,  serves  as  a  means  of  ready  identification  in  drilling.  The  formation  is 
nearly  devoid  of  fossils  so  that  this  common  means  of  recognition  of  beds 
is  not  available. 

The  St.  Peter  sandstone  is  encountered  in  the  Morris  quadrangle  at 
depths  ranging  from  less  than  125  feet  to  about  600  feet.  This  wide  range 
is  due  in  part  to  the  inequality  in  the  amount  of  cover  of  surficial  materials, 
and  in  part  to  difference  in  altitude  of  the  surface  of  the  sandstone.  This 
difference  in  altitude  is  itself  due  largely  to  the  southeast  dip  of  the  formation, 
but  probably  in  part  also  to  erosional  irregularities  in  the  surface  of  the  rock. 
A  table  is  appended  giving  these  data  and  also  the  elevation  of  the  sur- 
face above  sea  level,  the  thickness  where  known,  and  the  character  of  the 
strata  above  and  below. 

The  thickness  of  the  formation  is  about  200  feet,  but  considerable  varia- 
tion is  shown  in  logs.  From  the  few  data  at  hand  it  is  not  clear  that  the 
variations  are  due  to  a  uniform  or  widespread  thickening  and  thinning  of 
the  bed,  since  the  fortuitous  disposition  of  the  wells  may  show  variations 
due  merely  to  erosional  irregularities  of  the  upper  surface  in  conjunction 
with  similar  irregularities  of  the  upper  surface  of  the  Shakopee  dolomite 
below.  If  the  last  two  factors  are  compensating,  the  Coal  City  and  Holder- 
man  wells  indicate  that  the  formation  is  thinner  in  the  southeast  part  of  the 
quadrangle.  An  extension  of  this  area  to  the  northeast  would  include  the 
thin  part  at  the  Minooka  "oil  well,"  on  DuPage  River,  where  only  110  feet 
of  St.  Peter  was  recorded.  That  this  is  a  belt  rather  than  a  wide  area  of 
thinner  sandstone  is  indicated  by  a  thickness  of  more  than  200  feet  at  Braid- 
wood,  farther  to  the  southeast.  In  this  connection  it  is  of  interest  to  note 
that  in  the  area  of  outcrop  of  the  St.  Peter  formation  west  of  the  quadrangle, 
there  is  no  evidence  of  erosional  irregularities  in  the  surface  of  the  formation 
of  more  than  40  or  50  feet.''' 

Since  all  data  on  the  St.  Peter  formation  in  the  Morris  area  are  from 
well  logs,  but  little  can  be  said  of  the  contact  of  this  formation  with  those 
above  or  below.  In  a  few  instances  drillers  have  noted  peculiarities  at  the 
upper  surface  which  are  of  interest. 

sCady,  G.  H.,  Structure  of  the  La  Salle  anticline:    111.  State  Geol.  Survey  Bull.  36.  p.  106,  1920. 


ORDOVICIAN    SYSTEM 


19 


Tabli-:  3. — Tabulated  well  data  on  St.  Peter  sandstone  for  Morris  Quadrangle. 


Location 

Depth 

Eleva- 
tion 

Thick- 
ness 

Contact  with  adjacent  beds 

Township 

Sec. 

Above 

Below 

KENDALL 
COUNTY 

Big  Grove 

(T.  35  N.,  R.  5  E.) 

24 

24 

27 

32 

3 
5 

10 
13 
13 
14 

15 
20 
23 
23 

23 

25 

26 
32 

12 
18 

19 
20 

24 
30 
30 
30 
30 
31 
32 
35 

123 
200 
181 

360 

170 

176 

180 

205 

255- 

198 

190 
214 
255 
238 

240 
330 

256 
268 

350 
250 

244 
100 

380 
281 
316 
233 
278 
287 
318 
344 

547 
480  + 
544 

360 

450 

489 

425 

395 

330  + 

407 

410 
411 
330 
347 

345 
260 

339 

350  + 

210 
330 

321 
368 

155 
279 
244 
327 
271 
263 
227 
181 

3  ft.  flint 

195 
268 

181   ft.  drift 

La  Salle 

(T.  34  N.,  R.  5  E.) 

GRUNDY   COUNTY 

Nettle  Creek 

25  ft.  limestone 

"common  surface" 

limestone 

(T.  34  N.,  R.  6  E.) 

47  ft.  Pennsvlvanian.  .  . 

10  ft.  limestone 

91  ft.  limestone 

185  ft.  limestone 

40  ft.  Platteville   +  49 
ft.  Galena 

76  ft.  limestone 

44  ft.  limestone 

139  ft.  limestone 

53  ft.  soapstone   +   74 

ft.  limestone  (Galena) 

125  ft.  limestone 

2  ft.  clay;  8  ft.  shale  60 

ft.  from  base 

116  ft.  limestone 

white     lime- 
stone 

Saratoga 

(T.  34  N.,  R.  7  E.) 

? 

? 

140   ft.    limestone   with 
clay  pockets  at  base. 

154  ft.  limestone 

(of  doubtful 

limestone 

accuracy) 

168  ft.  limestone 

limestone 

133  ft.  limestone 

limestone 

limestone 

1  ft.  black  clay 

limestone 

20 


GEOLOGY   OF    MORRIS    QUADRANGLE 


Table  3. — Tabulated  well  data  on  St.  Peter  sandstone  for  Morris  Quadrangle — Continued. 


Location 


Township 


Anx  Sable 

(T.  34  N.,  R.  8.  E.) 


Erienna 

(T.  33  N.,  R.  6  E.) 


Sec. 


Norman 

(T.  33  N.,  R.  6  E.) 


Morris 

(T.  33  N.,  R.  7  E.) 


Goose  Lake 

(T.  33  N.,  R.  7  E.) 

Goose  Lake 

(T.  33  N.,  R.  8  E.) 

Mazon 

(T.  32  N.,  R.  7  E.) 

Braceville 

(T.  32  N.,  R.  8  E.) 

WILL  COUNTY 


Channahon 

(T.  34  N.,  R.  9  E.) 


(T.  32  N.,  R.  9  E.) 


9 
10 
30 

3 
4 
8 

10 
13 
15 
15 

22 
22 
22 
27 

4 
4 

4 

4 


Depth 


322 
549 
263 

290 

294 

260 

296 

363- 

443 

217 

374 
400 
391 
409 

317 
316 
315 
330 


12   600  + 


18 


10 


3? 


504 


554 


600 


440 


645 


Eleva-  Thick- 
tion   ness 


263 

50 

262 

305 
316 
340 

284 

137  + 
47 
283 

221 
200 
210 
196 

203 
204 
205 
193 

-50 


31 


16 


■40 


■75 


175 


150 


110 


Contact  with  adjacent  beds 


Above 


limestone  (?)... 
90  ft.  limestone, 
limestone  (?)... 


80  ft.  limestone . 

limestone 

105  ft.  limestone. 

limestone 

limestone 

? 

limestone 


(?)  18  ft.  clay  (pocket? 

limestone 

limestone 

"gumbo"  over  1  ft.  rock 


limestone 

limestone 

shaly  limestone. 


limestone. 


hmestone. 


limestone. 


210      limestone. 


Below 


30  ft.  gray 
shale 

limestone 
with  green 
shale 


ORDOVICIAN    SYSTEM  21 

Inspection  of  the  preceding  table  shows  clay,  recorded  variously  as  "black 
clay,"  "gumbo,"  "clay  pocket,"  etc.,  in  four  wells  so  arranged  as  to  suggest 
that  their  geographic  relation  has  no  significance.  The  three  feet  of  flint  from 
one  well  may  be  interpreted,  in  the  absence  of  samples,  as  a  silicified  phase 
of  the  overlying  Platteville  limestone,  or  as  an  especially  well  cemented 
upper  part  of  the  St.  Peter  sandstone  itself.  In  two  cases,  both  a  short 
distance  west  of  the  north  end  of  the  quadrangle,  the  covering  is  loose,  sur- 
ficial  material  indicating  a  removal  of  the  overlying  bed  rock  in  that  region. 

In  the  logs  of  the  six  wells  passing  through  the  St.  Peter  sandstone 
none  records  any  peculiarity  at  the  sandstone-dolomite  contact  below. 

Sufficient  data  are  at  hand  to  show  with  fair  accuracy  the  contour  of 
the  upper  surface  of  the  formation,  but  the  delineation  of  the  lower  surface 
can  not  be  attempted.  For  a  distance  of  25  miles  in  a  general  east-west 
line,  however,  the  decline  of  the  upper  surface  eastward  amounts  to  435 
feet,  or  17.4  feet  per  mile.  The  lower  surface  slopes  450  feet  in  the  same 
direction,  or  at  the  rate  of  18  feet  per  mile.  It  appears  therefore  that  the 
dip  of  the  formation  must  be  of  approximately  this  amount.  The  maximum 
slope,  however,  appears  to  be  to  the  southeast  (see  contours  on  Plate  III), 
in  which  direction  it  amounts  to  more  than  28  feet  per  mile.  From  the  data 
cited  above,  this  is  probably  near  the  true  dip  of  the  formation. 

PLATTEVILLE    LIMESTONE 

Above  the  St.  Peter  sandstone  over  most  if  not  all  the  Morris  quad- 
rangle lies  the  Platteville  limestone.  This  formation  is  characteristically 
non-magnesian  in  contrast  to  the  other  calcareous  members  of  the  Ordo- 
vician  and  Silurian  systems  which  are  largely  dolomitic.  This  member 
does  not  outcrop  in  the  region,  however,  and  its  probable  character  here 
must  be  determined  from  exposure  elsewhere.  Because  of  its  lithologic 
similarity  to  the  overlying  member  of  the  Ordovician,  the  Galena  dolomite, 
drillers  do  not  usually  distinguish  the  two  formations.  Examination  of  drill 
cuttings  renders  the  identification  of  the  Platteville  possible  in  some  in- 
stances. It  is  customary,  on  account  of  their  similarity,  to  place  the  two 
formations  together  as  the  Platteville-Galena.  In  the  records  of  four  bor- 
ings, from  two  of  which  samples  of  drill  cuttings  have  been  examined  by 
members  of  the  Survey,  it  is  possible  to  reach  tentative  conclusions  regard- 
ing the  Platteville.  These  data  are  presented  in  tabular  form  below,  and 
a  generalized  section  of  the  Platteville"  is  appended  for  comparison. 

Lithologically  there  is  considerable  similarity  in  these  sections.  In 
each  case  the  Galena  is  represented  by  a  considerable  thickness  of  material 
of  uniform  character,  while  the  lower  portion  of  the  record  shows  variation 
in  comjxjsition  in  relatively  short  distances.     This  difference  in  character  of 

'Grant,  U.  S.,  and  Burchard.  E.  F.,  U.  S.  Geol.  Survcv  .-\tlas.  Lancaster-Mineral  Point  folio  (Xo.  14  5) 
p.  4,  1907. 


12 


GEOLOGY   OF    MORRIS   QUADRANGLE 


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ORDOVICIAN    SYSTEM  23 

material,  indicating  changed  conditions  of  sedimentation,  is  suggestive  of 
a  difiference  in  age,  and  the  lower  beds  are  tentatively  assigned  to  the 
Platteville. 

On  this  basis  the  Platteville  formation  in  this  region  includes  a  lime- 
stone phase,  possibly  with  some  shale  above  and  a  dolomitic  phase  below. 
The  basal  sandy  shale,  which  typically  is  sharply  delimited  by  the  overlying 
calcareous  beds  but  grades  into  the  St.  Peter  sandstone  below,  was  appar- 
ently not  distinguished  by  the  drillers  in  the  cases  cited  above.  In  some 
other  instances,  however,  there  is  noted  a  blue  shaly  phase,  commonly  re- 
corded as  the  "blue  St.  Peter,"  at  the  contact  of  St.  Peter  sandstone  and 
the  overlying  beds.  It  is  possible  that  this  phase  is  present  in  most  places, 
but  is  not  recognizable  in  the  drilling  records. 

As  indicated  in  the  discussion  of  the  St.  Peter  sandstone,  the  data  from 
this  region  are  in  harmony  with  the  conception  of  an  unconformity  ac- 
companied by  erosional  irregularities  of  surface  between  that  formation 
and  the  Platteville.  A  similar  relationship  between  the  Platteville  and  the 
overlying  Galena  is  suggested  but  not  proved  by  the  data  from  this  region. 

GALENA    DOLOMITE 

The  top  member  of  the  Middle  Ordovician  is  the  oldest  formation  ex- 
posed in  the  Morris  quadrangle.  It  is  the  dolomite  which  outcrops  in  several 
places  north  of  the  "Coal  Measures"  area.  At  no  point  is  an  extensive 
section  exposed  and  the  paucity  of  outcrops  makes  impossible  the  accurate 
correlation  of  such  beds  as  do  appear.  The  general  character  of  the  forma- 
tion can  be  determined,  but  the  relative  amounts  of  the  different  kinds  of 
beds  can  not.  One  of  the  most  extensive  outcrops  is  in  the  extreme  north- 
west part  of  the  quadrangle  on  the  headwaters  of  Saratoga  Creek,  in  sec.  36, 
T.  35  N.,  R.  6  E.  Here,  for  a  distance  of  about  400  yards  on  each  side 
of  the  wagon  bridge,  the  stream  has  cut  a  shallow  channel  in  the  resistant 
dolomite,  which  at  this  place  has  a  thin  cover  of  loose  material. 

The  rock  is  finely  crystalline  to  earthy  in  texture.  Although  probably 
gray  when  fresh,  the  exposures  show  a  buff  color,  with  pinkish  tone  in 
places.  On  more  complete  weathering  the  rock  becomes  a  yellow-brown 
porous  mass  in  which  are  irregularly  shaped  pockets  containing  small  crystals 
of  calcite.  The  presence  of  small  stringers  of  calcite  and  of  small  areas 
(one-half  a  square  inch  in  size)  in  which  uniform  orientation  of  cleavage 
planes  obtains,  indicates  recrystallization  subseciuent  to  deposition. 

Yellowish-white  to  white  chert  is  not  rare,  being  apparently  confined 
to  the  bedding  planes.  The  rock  is  thin-bedded,  especially  in  the  upper, 
more  weathered  portion,  4  inches  being  the  maxinuun  thickness  observed. 
In  the  outcrop  probably  less  than  15  feet  of  strata  are  exposed,  although 
the  uniform  character  of  the  beds  makes  this  determination  doubtful.    Above 


24  GEOLOGY    OF    MORRIS    QUADRANGLE 

the  bridge  the  dolomite  shows  a  low  downstream  dip  for  about  100  yards, 
but  elsewhere  is  apparently  quite  flat.  A  shallow  gully  some  rods  to  the 
east  exposes  about  6  feet  of  dolomite  which  there  shows  a  southwest  dip 
of  about  1°.  The  very  limited  outcrop  gives  no  suggestion  as  to  the  dis- 
tance over  which  this  structure  is  maintained.  Jointing  is  prominent  locally, 
the  better  developed  planes  trending  N.  56°  W.  These  have  been  the  site 
of  pronounced  weathering  in  places,  giving  bands  of  yellow  clay  residue  as 
much  as  2  inches  wide.  The  formation  is  here  sparsely  fossiliferous.  A 
few  crinoid  segments,  one  flat-valved  brachiopod,  a  mold  of  a  straight 
cephalopod,  and  numerous  fragments  of  the  coral,  Colmnnaria  officinalis, 
are  all  that  have  been  seen. 

From  lack  of  marked  irregularity  in  the  surface  of  the  dolomite  over 
the  whole  exposure,  planation  by  glacial  action  is  suggested.  Although  the 
exposure  shows  wear  by  streams  rather  than  by  ice,  two  small  patches  have 
smoothed  and  striated  surfaces.  On  these  two  the  grooves  and  striations 
trend  uniformly  S.  56°  W. 

An  exposure  of  about  equal  stratigraphic  thickness  is  found  in  the 
abandoned  quarry  on  the  north  outskirts  of  Lisbon  village.  Here  the  fol- 
lowing section  is  obtained : 

Section  of  Galena  dolomite  in  abandoned  quarry  near  Lisbon  Thickness 

Ft.  In. 

Soil,  gray  black 10 

Clay,  gray  brown 1       2 

Dolomite,  well  weathered,  light  yellow  brown  (crumbles  easily,  variable 

thickness) 3       6 

Dolomite,  cream  gray,  more  regular  bedding  and  jointing 5       6 

Dolomite,  probably  same  as  above,  but  discolored  from  long  submergence        3       0 

Lithologically  the  rock  is  quite  like  that  previously  described.  While 
much  greater  variation  in  texture  and  color  is  to  be  seen,  it  seems  to  be 
due  to  differences  developed  in  weathering.  No  color  or  texture  appears 
to  be  confined  to  any  one  bed  or  group  of  beds.  Only  slight  traces  of  fossils 
were  noted,  mainly  crinoid  segments,  although  a  loose  fragment  showed 
Dalmanclla  testudinaria.  In  this  nearly  circular  quarry,  about  60  feet  in 
diameter,  the  beds  are  flat-lying. 

Two  and  one-half  miles  east  of  this  quarry,  in  section  21  of  Lisbon 
Township,  another  opening  in  the  Galena  has  been  made.  The  operation 
of  this  quarry  in  1920  exposed  the  following  section: 

Section  measured  in  sec.  21,  Lisbon  Twp.  Thickness 

Feet 

Drift 1 

Dolomite,  weathered,  buff  (thickness  2-10  feet) 5 

Dolomite,  more  slabby  than  above,  buff 5 

Dolomite,  fresh,  pinkish  gray,  finely  crystalline 5 


ORDOVICIAN    SYSTEM 


In  the  beds  exposed  there  are  no  marked  differences  except  those  due 
to  weathering.  The  pink  tone  is  very  faint  in  the  fresh  rock,  which  is  dis- 
tinctly gray.  From  it  are  derived  by  weathering  various  cream,  buff,  brown 
and  green  tints  in  great  irregularity.  The  upper  beds  show  the  same 
weathering  effects  as  were  described  for  the  Lisbon  quarry,  but  here  the 
depth  to  which  the  weathering  has  progressed  is  less  uniform.  Relatively 
fresh  rock  appears  at  the  surface  at  the  north  end  of  the  quarry,  while  at 
the  south  end  an  advanced  stage  of  weathering  has  extended  to  a  depth  of 
10  feet.     In  the  fresher  part  the  bedding  planes  are  about  8  inches  apart. 

These  beds  show  no  sets  of  joints  but  instead  are  broken  by  a  few 
irregularly  disposed  cracks,  essentially  vertical.  The  greater  abundance  of 
these  in  places  is  probably  related  to  the  variation  in  depth  to  which  weather- 
ing has  progressed.  Clay  seams  filling  these  joints  to  a  depth  of  10  to  12 
feet  are  common. 

Careful  examination  reveals  a  few  fossils.  Without  exception  the 
calcium  carbonate  has  been  leached  from  the  shells,  leaving  casts  and  molds. 
In  this  connection  it  is  of  interest  to  note  the  presence  of  crystals  of  calcite 
up  to  2  inches  in  diameter  in  the  rock,  but  not  evidently  filling  cavities 
The  fossils  are  listed  below : 

Fossils  from  the  Galena  dolomite  collected  in  sec.  36,  T.  35  N.,  R.  6  E. 

Ambonychia  sp.  cf.  affinia 

Liospira  sp.  cf.  vitruvia 

Lophospira  sp. 

Murchisonia  sp. 

Receptaculites  oweni 

Rhynchotrema  increbescens 

Trochonema  sp.  undescribed  cf.  stroporalliis 

In  the  abandoned  quarry  at  Central  (fig.  15).  a  little  more  than  a 
mile  to  the  south,  only  the  upper  5  feet  can  be  examined.  The  rock  dump, 
however,  shows  finely  crystalline,  pinkish-gray  rock,  weathering  buff,  with 
iron  stains  and  considerable  calcite,  and  also  bluish-gray  rock  which  has  a 
distinctly  pink  tone  in  some  places.  The  texture  of  the  two  is  identical, 
being  in  part  massive  and  in  part  finely  crystalline.  It  is  probable  that  the 
darker  rock  comes  from  the  lower  part  of  the  ([uarry,  which  is  reported  to 
be  35  or  40  feet  deep.  In  that  case  it  is  likely  that  the  upper  rock  is  merely 
the  weathered  equivalent  of  the  lower.  This  relation  is  similar  to  that 
noted  for  the  quarry  to  the  north.  One  distinction  between  these  exposure^ 
is  the  depth  to  which  weathering  has  advanced.  In  the  quarry  to  the  north 
an  advanced  stage  has  been  reached  at  a  depth  of  10  feet  and  all  calcite 
of  shells  has  been  removed.  Here  relatively  fresh  rock  appears  at  the 
surface  on  all  sides  and  the  fossils  show  no  leaching.  A  related  feature 
of  difference  is  the  fact  that  in  the  latter  case  the  surface  has  been  planed 
off  by  the  ice,  while  in  the  former  this  is  not  evident. 


26  GEOLOGY    OF    MORRIS    QUADRANGLE 

The  fossils  include  the  following: 
Fossils  from  the  Galena  dolomite  in  the  old  quarry  at  Central  in  sec.  28,  T.  35.  N.,  R.  7  E. 

Eccyliopterus  sp. 
Leptaena  rhomboidalis 
Orthis  plicatella 
Refinesquina  alternata 
Trochonema  (?)  sp. 
Zygospira  recurvirostra 

Other  exposures  of  essentially  the  same  type  of  rock  are  in  a  run  three- 
quarters  of  a  mile  west  of  Central  on  the  north  line  of  section  32  and  in 
an  abandoned  quarry  1^  miles  east  on  the  east  line  of  section  34. 


Fig.  15.     Quarry  in  Galena  dolomite  at  Central,  Kendall  County 

But  three  other  exposures  of  this  formation  have  been  noted  in  the 
Morris  quadrangle.  In  section  24  of  Saratoga  Township  (T.  34  N.,  R.  7  E.) 
there  is  an  abandoned  quarry  south  of  Ridge  Road.  The  rock  here  is  of 
gray-brown  color,  fine  to  medium-fine  crystalline  texture,  and  contains  con- 
siderable pyrite  in  small  grains.  On  weathering,  an  irregular  surface  and 
a  marked  rusty  spotting  is  developed.  The  beds  are  sparsely  fossiliferous. 
About  a  mile  to  the  northeast,  in  section  18  of  Aux  Sable  Township 
(T.  34  N.,  R.  8  E.),  Collins  Run  exposes  Galena  dolomite  at  the  wagon 
bridge  near  the  Walley  School.  Not  more  than  two  feet  of  beds  are  ex- 
posed and  they  show  no  distinguishing  characteristics.  The  rock  is  gray,  near 
tan  on  some  surfaces,  and  has  a  faint  pink  tone  in  others.  Weathering 
brings  out  the  pink  color  and  prodvices  also  a  yellow-brown  stain,  which 
is  pronounced  along  joint  planes  and  in  cavities.     Some  calcite  is  present. 


JRDOVICIAN    SYSTEM 


27 


28  GEOLOGY    OF    MORRIS    QUADRANGLE 

but  not  as  much  nor  in  as   large  masses   as   in  the   Central  quarry  beds. 
Fossils  are  neither  rare  nor  abundant.     Those  gathered  include : 

Fossils  from  the  Galena  dolomite  in  sec.  18,  T.  34  N.,  R.  8  E. 

Bellerophon  species 
Illaenus  americanus  (?) 
Lophospira  sp. 
Orthoceras  sp. 
Rhjnchotrema  increbescens 

The  most  southeastern  outcrop  of  the  formation  is  in  the  bed  of  Aux 
Sable  Creek  in  sec.  19,  T.  34  N.,  R.  8  E.,  north  of  the  Rock  Island  tracks. 
This  comprises  several  isolated  patches  of  rock  smoothed  by  glacial  action 
but  with  that  surface  largely  modified  by  later  stream  action.  The  fresh 
rock  is  not  exposed  but  seems  to  be  gray  dolomitic  limestone,  finely  crystal- 
line to  dense  in  texture.  It  has  a  gray  to  dirty  white  surface  color  and 
weathers  to  bufif  below.  Pyrite  is  rather  common  throughout  the  beds, 
giving  rise  to  a  "pockety"  surface  through  weathering  and  stream  wear. 
From  these  outcrops  there  appear  to  be  two  phases  of  the  formation  repre- 
sented. A  lower,  more  pyritiferous  part,  and  an  upper  part  comprising 
more  fossiliferous  beds.  There  is  no  indication  from  these  outcrops  of  the 
area  over  which  these  phases  are  distinct.  The  only  fossils  noted  were 
Rafincsqiiina  alternata  and  Dclnmnella  testudinaria. 

The  beds  at  this  place  appear  to  have  a  slight  dip  to  the  northwest. 

Logs  of  wells  in  the  Morris  area  show  a  much  wider  distribution  of 
the  Galena-Platteville  formation  than  is  indicated  by  the  outcrops.  In  fact, 
every  section  in  the  quadrangle  shows  some  portion  of  this  formation, 
although  covered  by  other  strata  in  most  places.  Its  probable  presence 
beneath  valley  fill  in  the  Illinois  valley  will  be  noted  in  connection  with 
the  Pennsylvanian  (fig.  16).  The  only  additional  lithologic  data  obtained 
from  a  study  of  logs  have  reference  to  certain  features  which  probably  are 
common  throughout  the  formation  but  of  local  rather  than  widespread 
development.  These  include  such  variations  from  the  normal  dolomite  as 
soft  bands  from  a  few  inches  to  several  feet  in  thickness ;  chert  bands ; 
thin  sandy  phases ;  and  cavities  or  pockets  commonly  lined  or  filled  with 
clay.  Some  of  these  cavities  are  several  feet  in  diameter  and  probably  are 
the  result  of  solution.  Pyrite  is  common  in  the  formation  but  has  no  ap- 
parent restriction  to  any  zone. 

As  a  result  of  the  combination  of  several  factors,  the  thickness  of  the 
Galena-Platteville  formation  ranges  from  400  feet  to  less  than  100  feet  within 
the  quadrangle.  Sufficient  data  are  not  at  hand  to  delineate  the  surface  in 
detail,  but  an  inspection  of  well  logs  brings  out  the  relationship  of  the  sev- 
eral factors  to  the  known  variation  in  thickness. 


ORDOVICIAN    SYSTEM 


29 


ELEVATION 
-600 


^>;;i.y;:^;v<;^_C:7-^?M°-'>°^'«V 

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^  -^  .  /  *  -  •  -  "  ^  *  ^  %^  r-v  .""  ^  •^--'  \  >  -"  *-%  -  -- 

-^^^  f^  T"^  'C^Z^  '     '^      J_~J25~ 

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^^^^^1 

'Z^P^'^'''^^  .'  .  ■     '.".'.■.'  St  P»»«'  .■  .■  .  Sandstone.'  ...     . "  .    .    . .'.'.•.■.■. 

..■.'..'.■...           ■ 

Fig.  17.    Underground  relations  in  southwestern  Saratoga  Township,  Grundy  County 


30  GEOLOGY    OF    MORRIS.    QUADRANGLE 

The  thickest  part  is  in  the  Coal  City  region,  and  from  there  north- 
westward the  fonnation  thins  so  that  a  short  distance  west  of  the  limits 
of  the  quadrangle  the  underlying  St.  Peter  is  the  uppermost  bed  rock.  This 
variation,  amounting  to  nearly  100  per  cent  of  the  total  thickness,  is  due  to 
plantation  of  the  formation,  which  has  a  slight  tilt  to  the  southeast.  Another 
variation,  more  pronounced  because  of  the  small  area  involved,  is  in  the 
southwest  part  of  Saratoga  Township  (34  N.,  7E.).  Here  a  group  of 
wells  shows  thicknesses  ranging  from  216  down  to  133  feet  in  one  square 
mile  (fig.  17 A).  Since  the  upper  surface  of  the  formation  shows  but  10 
feet  of  relief  in  this  area,  the  observed  variation  in  thickness  is  caused  by 
the  unevenness  of  the  lower  surface.  Consideration  of  the  structure  of 
the  St.  Peter  formation  over  the  quadrangle  leads  to  the  inference  that  this 
variation  is  the  result  of  planation  of  the  beds  where  upwarped  (fig.  17B). 
By  an  alternative  interpretation  of  these  data  the  indicated  relief  of  the 
sandstone  surface  suggests  a  measure  for  the  difference  in  original  thick- 
ness of  the  overlying  calcareous  series  (fig.  17C). 

There  are  also  variations  clearly  due  to  unevenness  of  the  upper  sur- 
face. Thus  in  the  city  of  Morris  wells  show  a  distinct  rise  of  the  surface 
of  the  dolomite  northwest  of  the  Illinois  which  corresponds  only  roughly 
to  the  increase  in  thickness  in  that  direction. 

One  other  factor,  the  effect  of  which  can  not  be  definitely  stated,  is 
that  involving  the  Platteville  formation  as  a  unit.  Too  little  is  known  of 
this  formation  to  warrant  other  than  very  general  deductions  as  to  its  thick- 
ness or  the  amount  of  erosion  it  suffered  before  the  deposition  of  the 
overlying  Galena.  It  is  probable,  however,  that  whatever  relief  was  de- 
veloped on  its  surface  was  compensated  by  a  corresponding  inequality  in 
deposition  of  the  Galena. 

The  absence  of  records  showing  the  elevation  of  both  the  top  and 
bottom  of  the  Galena-Platteville,  in  an  area  where  it  has  not  obviously  suf- 
fered erosion,  precludes  any  inference  as  to  the  structure  of  this  formation. 
It  may  therefore  be  assumed  to  have  a  structure  similar  to  that  of  the 
underlying  St.  Peter  sandstone. 

UPPER  ORDOVICIAN   SERIES 

In  the  Morris  quadrangle,  as  elsewhere  in  Illinois,  the  Upper  Ordo- 
vician  series  is  represented  by  but  one  formation,  the  Maquoketa,  which  is 
considered  to  be  of  Richmond  age. 

MAQUOKETA    FORMATION' 

Exposures  of  the  beds  of  this  formation  are  limited  to  the  northeast  part 
of  the  Morris  area.  One  group  of  exposures  is  to  be  seen  from  the 
Grundy  County  line  northward  beyond  the  limits  of  the  quadrangle,  in  the 


OUnOVICIAN    SYSTEM 


31 


bed  and  low  banks  of  Aux  Sable  Creek  (fig.  18).  Becau.se  of  the  low 
relief  of  the  region  and  the  nearly  horizontal  attitude  of  the  beds,  only  a 
limited  stratigraphic  section  can  be  measured  in  the  whole  distance. 

Another  group  of  exposures  is  in  the  vicinity  of  the  head  of   Illinois 
River,  including  the  southea.st  part  of  Aux  Sable  (T.  34  N.,  R.  8  E.)  and 


nmirmrwm'mmmm 


Hl^\    >^^3J 

wNv"" 

iHb^ 

gj 

WiS^^^^S^^^ 

ttSE 

^S, 

^wfll 

^H| 

^mlKWHh&r.! 

^?s. 

^H 

H 

iCjS:>a-  :y  "^T^f^  w^-  • 

ilH 

Fig.  IS.     .'^u.x  Sable  Creek  at  Shiirtlitfe  BriclKe.  Kendall  County 

A.  Maquoketa  limestone  in  bed  of  creek 

B.  Ponding  of  creek  above  oiilcroi)  shown  in  .\ 

the  northeast  part  of  Goose  Lake  (T.  v34  N.,  R.  8  E.)  townships.  The  out- 
crops, with  one  unimportant  exception,  are  the  tops  of  low  rock  knolls  which 
here  and  there  protrude  through  the  thin  cover  of  later  deposits,  so  that  but 
little  knowledge  can  be  added  to  the  stratigraphy  as  determined  from  the  Aux 
Sable  Creek  section. 


32  GEOLOGY    OF    MORRIS    QUADRANGLE 

The  exposed  rocks  include  beds  of  calcareous  shale  and  of  impure  as 
well  as  of  relatively  pure  limestone.  The  shale  is  thin-bedded,  mainly  without 
grit,  light  to  dark  gray,  and  weathers  to  a  flaky  incoherent  mass.  Con- 
sequently it  is  seen  only  where  protected  by  a  capping  ledge  of  limestone. 
The  limestone  shows  considerable  variety  of  texture  from  dense  to  coarse- 
grained. Medium-gray  when  fresh,  it  develops  a  bufif  to  brown  weathered 
surface  which  etTectually  conceals  both  textural  and  color  distinctions  be- 
tween beds  in  most  exposures. 

Characteristically  this  formation  contains  an  abundance  of  fossils,  in- 
cluding crinoids,  bryozoans,  brachiopods  and  trilobites,  but  some  strata  are 
practically  devoid  of  organic  remains.  This  lack  is  especially  noticeable 
in  the  shale  phases. 

All  beds  of  this  formation  appearing  along  Aux  Sable  Creek  within  the 
quadrangle  are  represented  in  exposures  in  section  3  of  Aux  Sable  Town- 
ship (T.  34N.,  R.  8E.).  A  total  of  17  feet  of  strata  are  exposed  in  the 
outcrop  near  the  w^agon  bridge.     The  section  follows : 

Section  of  Maquoketa  beds  exposed  along  Aux  Sable  Creek  Thickness 

Ft.  In. 

14.     Limestone,  coarse,"  gray  brown,  no  fossils,  stylolitic 6 

13.     Limestone,  coarse,  grayish  brown,  fossils  common,  beds  10  inches  thick.  .        2  6 

12.     Limestone,  medium  coarse,  gray,  fossils  less  common  than  above 4  0 

11.     Limestone,  slightly  finer  than  No.  12,  tan,  few  fossils,  slabby  on  weathering       1  6 
10.     Limestone,  medium  fine,  gray  tan,  fossils  abundant,  usually  includes  a 

2-inch  shaly  layer  about  1  foot  above  base 1  6 

9.     Limestone,  medium  coarse,  gray,  fossils  abundant  on  bedding  planes 1  6 

8.     Limestone,  shaly,  thin  bedded,  somewhat  uneven  but  persistent 2 

7.     Limestone,  medium  coarse  and  like  No.  9 2  6 

6.     Shale,  calcareous,  gray,  soft,  thin  bedded,  varies  from  2  inches  to 0  6 

5.     Limestone,  fine,  nearly  dense,  pinkish  gray,  fossils  abundant 0  3 

4.     Shale,  like  No.  6 0  6 

3.     Limestone,  like  No.  5 0  3 

2.     Shale,  like  No.  6 0  9 

Concealed  (possibly  shale) 0  6 

1.     Limestone,  like  No.  5  (base  concealed) 0  3 


i: 


a  In  field  examination  of  sediments,  the  texture  has  been  classified  as  follows:    coarse,  medium  coarse 
medium  fine,  fine,  and  dense. 

The  beds  of  the  above  section  are  readily  grouped  on  a  lithologic  basis 
into  two  divisions,  an  upper  of  more  or  less  crystalline  limestone  beds 
(Nos.  14-7)  and  a  lower  of  alternating  shales  and  dense  limestones  (Xos, 
6-1).  While  the  former  is  fairly  uniform  in  character  the  latter  shows 
considerable  lithologic  variation  in  short  distances.  This  is  due  to  the  change 
in  relative  amounts  of  limestone  and  shale  in  the  division  rather  than 
to   the   introduction   of    any   other   types   of    sediments.    The    limestone   is 


ORDOVICIAN    SYSTEM  33 

clearly  in  lenses,  or  in  nodules  of  lenticular  shape,  so  that  adjacent  sections 
bear  but  little  resemblance  to  one  another.  In  the  northwest  part  of  section 
3,  Aux  Sable  Township,  the  exposure  shows  but  two  6-inch  lenses  in  4 
feet  of  strata  below  the  lowest  crystalline  limestone,  while  at  the  next  bend 
upstream,  100  yards  distant,  the  outcrop  shows  seven  such  lenses  in  6  feet 
of  beds.  From  this  latter  outcrop  it  is  clear  that  the  lower  group  may  be 
extended  to  include  an  additional  3  feet  of  strata,  making  the  total  thick- 
ness exposed  approximately  20  feet. 

Differences  in  the  degree  of  weathering  of  these  dense  limestone  lenses 
result  in  marked  color  variations  which,  not  being  confined  to  certain  beds, 
confuse  rather  than  clarify  stratigraphic  distinctions. 

Local  up-  or  down- warps  of  these  beds  bring  in  one  place  the  crystalline 
limestone  beds,  in  another  the  dense  limestone-shale  phase  to  the  surface, 
but  so  far  as  can  be  determined  no  beds  stratigraphically  above  or  below 
the  section  given  are  exposed.  Dips  as  high  as  5°  are  maintained  for  a 
few  feet,  but  the  dip  in  one  direction  is  in  every  instance  compensated  by 
dip  in  the  opposite  direction  within  a  short  distance. 

The  fossil  content  of  these  beds  is  of  great  interest.  A  considerable 
number  of  species  of  crinoids,  bryozoans,  brachiopods  and  trilobites  are 
represented  in  the  exposures  which  have  not  yet  been  given  the  detailed 
study  they  deserve.  No  attempt  was  made  in  this  investigation  to  collect 
fossils  systematically,  but  the  great  profusion  of  bryozoan  forms  was  fre- 
quently noted  as  a  characteristic  of  the  strata  of  this  formation.*^  Aside 
from  these  and  the  crinoids,  neither  of  which  were  especially  studied,  the 
more  common  forms  were  the  following: 

Bellerophon  sp.  Orthoccras  sp. 

Calymene  senarius  Plectambonites  sericeiis 

C.  christyi  Pterinea  sp. 

Dalmanella  sp.  cf.  Meeki  Rafinesqiiina  altcrnata 

Dinorthis  subqiiadrata  Rhynchotrcma  capax 

Hebertella  occidentalis  Strophomena  planaodorsata 
Isotelus  maximiis 

South  of  the  Illinois-IMichigan  Canal  and  west  of  the  head  of  Illinois 
River  there  is  an  area  in  which  the  Maquoketa  limestone  is  almost  at  the 
surface.  In  the  soutli  half  of  section  22  rock  was  met  at  shallow  depth  in 
digging  the  canal.  Along  the  road  a  few  rods  to  the  south  the  limestone 
comes  to  the  surface  for  a  quarter  of  a  mile.  Here  it  has  the  usual  pinkish- 
buff  color  on  exposed  surfaces.  Fresh  samples  show  this  to  be  medium 
fine-grained  (average  less  than  1  mm.  diam.)  relatively  pure  limestone, 
medium  gray,  and  containing  irregular  veinlets  of  calcite.  The  hand  lens 
reveals  scattered  grains  of  pyrite  (one  to  a  square  inch)  and  less  com- 
monly small  black  particles  of  an  undetermined  substance.     Some  loose  frag- 

8Mr  C.  R.  Schroyer,  formerly  of  the  Illinois  State  Geological  Survey,  has  studied  this  bryozoan  fauna 
extensively.     His  report,  not  yet  completed,  describes  many  new  forms.     (Personal  communication.) 


34  GEOLOGY    OF    MORRIS    QUADRANGLE 

ments  showed  the  stylohtic  structure  noted  in  the  uppermost  Ijeds  of  the 
Aux  Sable  Creek  section. 

About  eight  feet  of  crystaUine  Hmestone  is  exposed  in  the  south  bank 
of  IlHnois  River  in  section  26  of  Aux  Sable  Township  (T.  34  N.,  R.  8E."). 
The  rock  here  is  similar  to  that  just  described  and  is  apparently  identical 
with  that  of  the  upper  division  of  the  Aux  Sable  Creek  section.  The  strati- 
graphic  relationship  of  these  beds  is  not  determinable  from  the  outcrops, 
although,  as  will  be  shown  later,  the  Illinois  River  beds  are  probably  some 
30  feet  higher  in  the  geologic  column  than  those  of  Aux  Sable  Creek. 

Other  exposures  of  this  crystalline  limestone  are  found  on  the  south 
bank  of  Illinois  River  in  section  25,  along  the  road  in  sections  34  and  35, 
and  are  reported  beneath  Pennsylvanian  beds  on  the  west  bank  of  Kankakee 
River  in  section  36.  Southward  toward  Goose  Lake,  two  outcrops,  one  in 
section  2  and  another  in  section  11,  reveal  the  presence  of  this  limestone 
at  shallow  depths  in  this  part  of  Goose  Lake  Township.  To  the  west,  south 
and  east,  however,  it  is  overlain  by  strata  of  the  "Coal  Measures." 

A  characteristic  of  the  limestone  phases  of  this  formation  is  the  promi- 
nence of  fossils  on  weathered  surfaces.  Not  infrequently  it  is  possible  to 
find  perfect  specimens  of  rafincsqu'ina  altcrnata.  rhynchotrcma  capax  and 
other  common  forms  lying  loose  on  the  exposed  ledges. 

x\dditional  data  both  as  to  the  extent  and  the  lithology  of  the  Ma- 
quoketa  formation  are  obtained  from  study  of  drill  records.  The  ^laquoketa 
formation  underlies  the  drift  in  a  strip  about  four  miles  wide,  extending 
northward  from  Illinois  River.  There  is  no  trace  of  its  former  extension 
to  the  west,  but  it  extends  east  beyond  the  quadrangle  to  the  DuPage, 
where  its  eastward  dip  carries  it  beneath  Silurian  limestone  of  Alexandrian 
age.  South  of  the  Illinois  there  is  a  tongue-like  projection,  but  slightly 
concealed  by  mantle  rock,  into  the  area  of  Pennsylvanian  strata,  termi- 
nating near  the  north  shore  of  Goose  Lake. 

Its  southward  extension,  where  concealed  by  Pennsylvanian  beds  as 
well  as  by  glacial  drift,  is  problematical.  A  boring  at  the  Goose  Lake  plant 
of  the  Haeger  Brick  and  Tile  Company  passed  through  50  or  more  feet 
of  limestone  and  shale,  probably  referable  to  the  Maquoketa.  Forty-five 
feet  of  shale,  referred  to  this  formation,  was  met  in  the  deep  boring  at 
Coal  City,  but  the  relation  of  these  beds  to  the  overlying  Pennsylvanian  is 
not  clear.  Even  less  satisfactory  is  the  record  of  a  boring  on  the  Holder- 
man  farm,  section  18  of  Goose  Lake  Township  (T.  33  N.,  R.  BE.),  where 
the  88  feet  of  "sandy  shale"  below  No.  2  coal  may  include  some  lower 
Maquoketa  shale. 

The  log  of  the  Walker  \vell,  two  miles  southwest  of  blazon,  has  been 
interpreted  by  Cady''  as  including  74  feet  of  shale  of  Maquoketa  age.     But 


'Cady.  G.  H.,  Coal  resources  of  District  I  (LongwalH:    111.  Coal  Mining  Investigations  Bull.  tO,  p.  119, 
1915. 


ORDOVICIAN    SVSTEM  35 

here,  as  in  the  Coal  City  log,  the  lack  of  a  satisfactory  horizon  marker  tor 
the  Pennsylvanian  part  of  the  record  leaves  the  position  of  the  lower  shales 
in  doubt.  There  must  be  admitted,  however,  the  possibility  that  Maquoketa 
beds  are  present  in  the  southeast  part  of  the  quadrangle.  The  bearing  of 
this  on  the  structure  of  this  formation  will  be  noted  later  in  the  discussion 
of  the  structure  of  the  Ordovician  beds. 

W'ithin  the  Morris  quadrangle  the  Maquoketa  comprises  an  upper  lime- 
stone phase  and  a  lower  shale  phase.  The  resistant  nature  of  the  fonner 
is  revealed  by  the  outcrops  described  above,  but  the  shale  phase  does  not 
appear  at  the  surface  within  the  quadrangle,  although  thin  shales  interbedded 
with  limestone,  as  previously  noted,  are  exposed  in  the  Aux  Sable  Creek 
section. 

The  thickest  part  of  the  Hmestone  member  is  near  the  head  of  Illinois 
River.  The  log  of  a  well  in  section  36  of  Aux  Sable  Township  (T.  34  N., 
R.  8E.)  gives  a  measured  thickness  of  44  feet,  but  a  total  of  65  feet  is 
probably  present  in  places  where  the  elevation  of  the  surface  is  correspond- 
ingly higher.  At  the  north  boundary  of  the  quadrangle  the  limestone  is 
less  than  30  feet  thick,  a  well  in  the  west  half  of  section  27  of  Seward 
Township  (T.  35  N.,  R.  8E.)  shows  but  8  feet,  while  less  than  half  a 
mile  west  no  limestone  at  all  is  recorded  above  the  shale  phase.  This  thin- 
ning to  the  west  is  obviously  due  to  the  erosion  of  the  beds  which  here  dip 
gently  eastward.  It  is  thus  clear  that  the  beds  of  the  Aux  Sable  Creek 
section  lie  near  the  base  of  the  Hmestone  member  which  has  its  western 
limit  less  than  a  mile  farther  west.  South  of  the  Illinois,  however,  where 
the  thickness  is  more  than  60  feet,  the  outcropping  beds  are  above  that 
horizon  by  at  least  the  ditYerence  in  thickness  or  more  than  30  feet.  More 
accurate  definition  of  the  stratigraphic  relation  between  these  beds  is  not 
practicable  with  the  present  data. 

The  lithologic  character  of  the  limestone-shale  phase  of  the  Aux  Sable 
Creek  section,  as  well  as  its  proximity  to  the  western  limit  of  the  limestone 
member,  suggests  that  this  lower  phase  is  the  transition  zone  between  the 
shale  and  limestone  members  of  the  Maquoketa.  (^n  this  interpretation 
there  is  no  unconformity  between  these  members. 

The  shale  member  has  a  maximum  known  thickness  of  65  feet,  which 
is  maintained  uniformly  eastward  beneath  the  overlying  limestone.  West 
of  this  protecting  cover  it  tliins,  extending  less  than  a  mile  beyond  the  west 
limit  of  the  limestone. 

Lithologically  the  lower  member  is  entirely  shale,  no  interbedded  lime- 
stones having  been  recorded  from  borings.  It  is  usually  medium  to  dark 
gray,  soft,  thin-bedded,  non-calcareous,  and  without  fossils. 

While  within  the  cpiadrangle  the  Maquoketa  shows  only  the  two  mem- 
bers alreadv  described,  well  records  farther  east  show  an  additional  mem- 


36 


GEOLOGY   OF   MORRIS   QUADRANGLE 


M 


o 

■^  .  . 

W  s  c  c 

to  9  °,  o 


rt   E  S  S 
.2  :s^u 


ORDOVICIAN    SYSTEM 


Z1 


ber,  the  presence  of  which  has  a  bearing  on  the  stratigraphy  of  the  area 
under  investigation. 

As  noted  earlier,  the  Ordovician  strata  at  the  east  side  of  the  quadrangle 
have  a  low  eastward  dip  which  carries  them  beneath  limestone  of  Silurian 
age.  East  of  the  edge  of  this  limestone,  as  shown  by  all  available  well 
logs,  the  Maquoketa  comprises  two  shale  members,  separated  by  a  lime- 
stone. These  relations  are  well  shown  by  a  northeast-southwest  section 
across  Kankakee  River  near  Lorenzo  (fig.  19),  based  on  the  following 
data: 

Table  5. — Logs  of  wells  ?jear  Lorenzo,  Will  County,  showing  thickness  of  strata  penetrated 


Formation 

Strata 

Section  18 

Wilmington 

Township 

Section  8 

Wilmington 

Township 

Section  34 
Channahon 
Township 

Edgewood 
(Silurian) 

limestone 

Feel 
eroded 

Feet 
29 

Feet 
33 

Maquoketa 

(Upper  Ordovi- 
cian) 

upper  shale 
limestone 
lower  shale 

eroded 

50 

not  penetrated 

76 
52 
61 

75 
35 
80 

While  the  scattered  wells  show  considerable  variation  in  the  thickness 
of  the  several  members,  they  indicate  a  thinning  of  the  limestone  to  the 
east  and  north,  and  even  greater  thickening  of  the  shale,  so  that  the  forma- 
tion as  a  whole  is  thicker. 

Since  this  upper  shale  is  45  feet  thick  about  a  mile  east  of  the  Morris 
quadrangle,  it  is  obviously  probable  that  it  extended  over  the  Minooka  area 
at  one  time,  if  indeed  it  does  not  now.  On  this  point  the  logs  are  not 
enlightening,  since  the  "surface,"  amounting  to  about  125  feet,  is  blue  clay 
till,  which  might  not  be  distinguished  in  drilling  from  the  Maquoketa  shale. 
Indeed,  it  is  not  improbable  that  this  upper  shale  may  have  furnished 
much  of  the  material  of  the  surface  till. 

The  relations  of  the  Upper  Ordovician  beds  to  the  overlying  Silurian 
limestones  has  been  noted,  but  the  details  of  the  contact  are  not  involved  in 
the  present  study  since  the  latter  rocks  do  not  outcrop  in  the  area. 

With  regard  to  the  contact  of  the  Maquoketa  and  the  underlying 
Galena,  but  little  can  be  said  since  the  only  data  are  from  a  small  number 
of  scattered  wells.  There  is  no  indication  of  discordant  relations  nor  of 
an  erosion  surface  of  even  moderate  relief.  Hence  it  may  be  assumed  that 
the  contact  is  essentially  a  plane  surface  and  represents,  if  not  a  conformity, 
at  luost  merely  a  slight  interruption  in  the  deposition  of  sediments  between 
Middle  and  Upper  Ordovician  epochs. 


38  GEOLOGY    OF    MORRIS    QUADRANGLE 

Elsewhere  in  the  Upper  Mississippi  Valley  the  exposed  contact  of  the 
two  series  shows  concordant  relations  also,  but  the  fossil  content  in  most 
places  indicates  a  gap  in  the  record.^*^ 

Pexxs\"lvaxiax  System 

Subdivisions  of  the  Pennsylvania}!  " 

McLeansboro: 

Calcareous  shales,  La  Salle  limestone,  Lonsdale  limestone,  sandy  shales,  No.  7  coal 
(locally  important). 
Carbondale: 

Shaly  sandstones,  shales,  some  fine  grained  limestone,  and  coals  Xos.  6,  5,  and  2. 
Pottsville: 

Mainly  sandstone  and  shale  with  some  limestone  and  thin  coals,  including  Xo.   1 
Hocally  important). 

"  Italicized  formations  are  represented  in  the  Morris  Quadrangle. 

The  rocks  of  the  Pennsylvanian  system  belong  to  the  "Coal  ]Measures" 
or  strata  associated  with  beds  of  coal.  They  are  the  youngest  solid  rock 
formations  of  the  quadrangle  and  underlie  the  drift  over  the  southwestern 
two-thirds  of  the  area. 

Disregarding  certain  small  outliers  to  be  noted  later,  the  north  limit 
of  these  beds  is  approximately  the  Grundy-Kendall  county  line  at  the  west 
and  the  head  of  Illinois  River  at  the  east.  This  large  area,  comprising  some 
150  square  miles,  probably  is  divided  into  two  parts  at  the  Illinois  valley,  at 
least  in  the  eastern  half  of  the  quadrangle,  by  an  old  valley  now  almost 
filled  with  sand  and  gravel  (fig.  16). 

The  presence  of  surficial  deposits  renders  the  exact  definition  of  the 
northern  boundary  difficult  and  on  Plate  III  the  contact  is  placed  as  accurately 
as  possible  on  the  basis  of  the  well  logs  at  hand.  More  detailed  knowledge 
doubtless  would  show  greater  irregularity  in  this  line,  but  certain  points 
on  it  are  definitely  fixed  by  exposures. 

Inspection  of  Plate  III  shows  the  Pennsylvanian  beds  to  overlie  the 
Galena  dolomite  at  the  west,  and  the  Maquoketa  formation  at  the  east,  with- 
out significant  difference  in  elevation.  This  relation  shows  that  the  older 
beds  had  been  somewhat  warped  and  then  subjected  to  erosion  for  a  period 
of  time  before  being  covered  by  the  deposits  of  Pennsylvanian  age.  An 
examination  of  the  geologic  map  of  the  state  brings  out  still  more  clearly 
this  overlapping  of  older  strata  by  Pennsylvanian  beds. 

The  Pennsylvanian  of  the  Morris  region  belongs  to  a  great  system  of 
strata  of  the  same  period  which  underHes  most  of  the  State  of  Illinois  as 
well  as  adjoining  parts  of   Indiana,   Kentucky,  Missouri  and   Iowa.    This 


"Grant,  U.  S.,  and  Burchard,  E.  F.,  U.  S.  GeoL  Survey  .\tlas,  Lancaster-Mineral  Point  folio  (Xo.  145), 
pp.  7-8,  1907. 


I'KN  N  S\  l.\.\  N  lA  X    S\  STi:  M 


39 


I'iK.  2U.      (  .irlidiul.ili-  s.iiKlsuiiu-  sliowiiiu  iliaraiti-rislic  thin  Ijcdilini;  and 
ri'sistaiu  U-ns»-s 


40  GEOLOGY    OF    MORRIS    QUADRANGLE 

whole  region  is  known  as  the  Eastern  Interior  Coal  Basin  in  distinction  from 
the  coal  areas  of  other  parts  of  the  United  States.  This  great  series  of  beds 
occupies  a  wide,  relatively  shallow  depression,  which  was  the  site  of  deposi- 
tion of  more  than  a  thousand  feet  of  sediments  including  several  valuable 
coal  beds.  The  basal  part  of  this  series  is  made  up  of  rocks  which  probably 
were  deposited  in  fresh  water  if  not  in  streams.  Above  these,  however, 
are  thin  limestones  containing  marine  fossils,  which  prove  that  at  several 
times  the  basin  was  invaded  by  the  sea.  None  of  these  limestones  has  been 
recognized  in  the  Morris  quadrangle,  and  hence  the  marine  origin  of  any 
of  the  Pennsylvanian  strata  there  may  be  questioned.  The  boundary  of 
the  Pennsylvanian  beds  in  the  Morris  area  is  a  portion  of  the  boundary 
of  the  Eastern  Interior  Coal  Basin  and  the  history  of  the  Pennsylvanian 
beds  here,  part  of  that  of  the  larger  area.  The  beds  which  outcrop  in  the 
vicinity  of  Goose  Lake  are  essentially  continuous  beneath  the  whole  basin 
and  come  to  the  surface  again  at  the  extreme  southern  limit  of  the  basin 
in  the  area  west  of  Shawneetown.  Examination  of  the  exposed  strata  in 
the  Morris  region,  therefore,  is  of  interest  in  connection  with  studies  of  the 
Eastern  Interior  Basin  as  a  whole. 

Pennsylvanian  rocks  are  exposed  in  more  or  less  isolated  patches  in 
most  of  the  area  which  they  underlie.  The  outcrops  are  almost  wholly  re- 
stricted to  the  courses  of  streams  and  hence  are  absent  in  the  southwestern 
part  of  the  quadrangle  where  the  thicker  drift  covering  has  not  been  cut 
through.  North  of  IlHnois  River  the  beds  are  exposed  (1)  on  Aux  Sable 
Creek  in  three  places  between  the  Rock  Island  tracks  and  the  Illinois- 
Michigan  Canal,  (2)  on  East  Fork  of  Nettle  Creek  in  the  city  of  Morris 
and  (3)  on  Nettle  Creek  in  sections  6  and  7  of  Erienna  Township  (T.  33  N., 
R.  7E.).  More  extensive  exposures  are  found  south  of  the  Illinois,  (1) 
along  Waupecan  Creek  in  Wauponsee  Township  (T.  33  N.,  R.  7E.),  (2) 
along  Mazon  River  and  its  tributaries  from  Pine  Bluff  Bridge  to  the  south 
limits  of  the  quadrangle,  (3)  withm  the  Goose  Lake  depression  and  (4) 
along  the  Kankakee  from  the  county-line  bridge  to  the  head  of  Illinois 
River. 

The  outcropping  beds  are  mainly  sandstone,  shale  and  intermediate 
types  of  rocks,  with  some  bituminous  layers,  but  almost  no  limestone. 

The  sandstones  are  variable  in  texture,  the  purer  ones  being  rather 
coarse.  Light  gray  when  fresh,  they  show  a  wide  range  of  weathering 
colors,  buff  or  brown  being  the  most  common.  Few  beds  are  massive,  most 
of  the  sandstones  are  thin-bedded,  and  cross  or  current  bedding  is  ex- 
tremely common.  (See  fig.  20.)  Ripple-marked  bedding  planes  are  not  rare. 
Calcareous  and  ferruginous  concretions  of  nodular  or  lenticular  shape  occur 
at  irregular  intervals  in  the  beds.  (See  fig.  21.)  These  range  from  minute 
masses  to  those  measured  in  rods.     In  composition  the  sandstones  show  little 


PENNSVLVANIAX    SYSTEM 


41 


variation.  They  are  composed  of  quartz  grains  with  abundant  mica,  but 
without  conspicuous  amounts  of  other  minerals.  .V  calcareous  cement  is 
common,  so  that  brisk  etTervescence  results  from  the  application  of  dilute 
hydrochloric  acid.  With  increase  in  the  amount  of  argillaceous  matter,  they 
grade   into   shaly   sandstones   and    from   those   into   sandy   shales    (hg.  22). 


Fia.    21.     Lenticular   concretions   in    Pennsylvanian 
Seds  along  Mazon  River 

These  are  rocks  of  finer  texture  but  similar  to  the  sandstones  in  color, 
structure  and  weathering  efifects. 

The  shales  are  of  very  fine  texture  where  pure,  but  coarser  wdiere 
gritty,  and  in  some  cases  have  an  appreciable  content  of  calcium  carbonate. 
In  color  they  range  from  very  light  gray  to  black,  being  blue,  green  or  even 
red  in  some  beds.  The  amount  of  organic  matter  present  is  greater  in  the 
darker  shales,  reaching  a  maximum  in  the  black  bony  layers  commonly 
associated  with  beds  of  coal. 

In  thickness  these  beds  range  from  less  than  10  feet  at  the  northern 
limit  of  the  Pennsylvanian  area  to  more  than  200  feet  farther  south.  This 
increase  is  not  gradual,  however,  because  of  tlie  unevenness  of  both  upper 


42 


GEOLOGY    OF    MORRIS    QUADRANGLE 


PENNSYLVANIAN    SYSTEM  43 

and  under  surfaces.  The  former  shows  a  total  relief  of  at  least  80  feet, 
with  a  maximum  of  50  feet  in  one  mile.  The  undulatory  character  of  the 
lower  surface  is  well  shown  at  the  contact  of  the  Pennsylvanian  and  Ordo- 
vician  strata  on  the  west  bank  of  Kankakee  River.  From  a  study  of  field 
relations  of  these  beds  in  the  adjoining  region,  it  is  clear  that  there  is  at  least 
20  feet  difference  in  the  elevation  of  the  base  of  the  Pennsylvanian  within 
short  distances.  Well  records  show  a  similar  surface  in  the  region  to  the 
west  and  south.  The  lower  surface  is  not  known  in  detail  south  of  Illinois 
River,  because  the  many  borings  have  stopped  in  most  instances  at  the 
horizon  of  No.  2  coal.  The  unevenness  of  the  surface  of  this  coal  is,  how- 
ever, suggestive  of  even  greater  relief  in  the  sub-Pennsylvanian  surface. 

The  rocks  of  this  system  are  not  abundantly  fossiliferous.  Locally  a 
great  profusion  of  forms  is  found,  plant  remains  being  more  common  than 
those  of  animals,  which  are  restricted  to  certain  strata,  notably  the  well- 
known  "fossil  beds"  of  Mazon  River.  No  marine  fossils  have  been  rec- 
ognized and  in  general  the  fossils  have  not  been  found  of  stratigraphic  value, 
and  no  faunal  lists  have  been  prepared.  It  is  possible  that  careful  study 
of  plant  remains  will  demonstrate  the  accuracy  or  inaccuracy  of  certain 
correlations  which  have  been  made  on  structural  and  lithologic  basis. 

The  Pennsylvanian  rocks  of  the  Illinois  basin  are  subdivided  for  con- 
venience into  three  formations,  which  in  ascending  order  are  called  the 
Pottsville,  the  Carbondale,  and  the  McLeansboro.  On  the  basis  of  an  exami- 
nation of  the  included  fossil  plants,  David  White^^  has  determined  that  the 
Pottsville  formation,  which  includes  all  beds  below  the  under  clay  of  No.  2 
coal,  are  of  approximately  the  same  age  as  the  Pottsville  of  the  Appalachian 
fields.  Similarly,  the  rocks  of  the  Carbondale,  including  all  beds  between  the 
underclay  of  No.  2  coal  and  the  top  of  No.  6  coal  are  referable  to  the 
Allegheny  epoch,  while  the  McLeansboro,  including  the  Pennsylvanian  rocks 
above  No.  6  coal,  corresponds  approximately  to  the  Conemaugh  formation 
of  Pennsylvania. 

These  subdivisions  can  be  recognized,  at  least  in  part,  in  the  Pennsyl- 
vanian strata  of  the  Morris  region.  The  key  horizon  is  No.  2  coal,  which  is 
quite  generally  present,  and  from  which  measurements  can  be  accurately 
made  both  up  and  down.  This  coal  marks  the  contact  of  the  Carbondale 
and  the  Pottsville.  The  separation  of  the  beds  of  the  Carbondale  from  those 
of  the  McLeansboro  is  rendered  difficult  because  of  the  absence  of  No.  6 
coal  throughout  this  portion  of  the  State.  Certain  beds  in  the  southwestern 
part  of  the  quadrangle,  associated  with  the  stratum  here  called  the  \\'aupecan 
sandstone,  are  possibly  to  be  classed  in  the  McLeansboro. 

POTTSVILLE   FORMATION 

Rocks  tentatively  assigned  to  the  Pottsville  underHe  the  drift  in  a  belt 
from  one  to  four  miles  wide  lying  just  south  of  and  parallel  to  the  edge  of 

"White,  David,  111.  State  Geol.  Survey  Bull.  8,  p.  268,  1908. 


44  GEOLOGY    OF    MORRIS    QUADRANGLE 

the  Pennsylvanian  area.  (See  PI.  III.)  The  variation  in  width  of  the  belt 
is  due  in  part  to  the  difference  in  thickness  of  the  beds  and  in  part  to  the 
difference  in  their  altitude.  The  only  outcrops  north  of  Illinois  River  are 
those  of  Aux  Sable  Creek,  but  south  of  the  river  the  beds  come  to  the  sur- 
face at  Devine,  Goose  Lake,  and  on  Kankakee  River,  just  above  the  head  of 
the  Illinois. 

All  available  drill  records  show  the  presence  of  this  formation  in  the 
area  southwest  of  this  belt.  No.  2  coal  being  reported  nowhere  as  resting  on 
the  underlying  Galena  dolomite.  As  was  pointed  out  in  the  discussion  of  the 
Ordovician  system,  unusual  thicknesses  of  shale  referred  to  the  "Coal  Meas- 
ures" may  include  some  Maquoketa  strata.  Examination  of  drill  cuttings  is 
the  most  satisfactory  method  of  determining  whether  or  not  the  Ordovician 
is  present,  but  at  the  present  no  such  samples  are  available.  The  character 
of  the  strata  immediately  above  the  Galena  dolomite  under  most  of  the  area 
northwest  of  Coal  City  indicates  that  they  are  Pennsylvanian  rather  than 
Ordovician. 

CORRELATION 

As  noted  above,  definite  correlation  of  Pottsville  strata  is  based  upon  the 
presence  of  the  overlying  coal  bed,  which  is  No.  2  of  the  Illinois  section.  In 
an  area  where  No.  2  is  not  present,  the  assignment  of  beds  to  a  definite  zone 
is  attended  with  difficulty.  This  is  the  condition  at  the  margin  of  the  Penn- 
sylvanian area,  where  so  far  as  indicated  by  their  areal  distribution,  the  strata 
may  belong  to  the  Pottsville,  or  to  some  portion  of  the  Carbondale  above  the 
zone  of  No.  2  coal,  or  to  the  McLeansboro.  While  little  hesitancy  might  be 
felt  in  assigning  to  the  Pottsville  the  beds  lying  north  of  the  city  of  Morris 
in  this  belt,  since  they  contain  no  coal  which  could  possibly  be  classed  as 
No.  2,  the  presence  of  a  coal  bed  in  section  19  of  Aux  Sable  Township 
(T.  34  N.,  R.  8  E.)  and  in  the  Goose  Lake  depression  makes  it  necessary  to 
exercise  great  care  in  the  correlation  of  the  strata  in  the  southeastern  part  of 
the  belt.  Nevertheless,  all  these  beds  are  tentatively  assigned  to  the  Potts- 
ville for  the  reason  noted  in  the  following  paragraphs : 

1.  Strata  of  undoubted  Pottsville  age  are  found  a  short  distance  south 
of  this  belt  wherever  the  rocks  below  No.  2  coal  have  been  penetrated.  Since 
they  show  no  thinning  at  the  edge  of  No.  2  coal  it  is  improbable  that  they  are 
abruptly  terminated  there. 

2.  The  lack  of  similarity  of  the  strata  of  this  belt  and  those  of  the 
known  Carbondale  area  to  the  south  suggests  a  difference  in  age.  The  sandy 
beds  of  the  northern  area  are  for  the  most  part  coarser  and  less  micaceous, 
composed  of  less  worn  and  less  well  assorted  material. 

3.  The  coal  beds  of  this  belt  apparently  are  not  connected  with  the 
main  body  of  No.  2  coal.  They  are  distinctly  lenticular,  pinching  out  on  all 
sides,  and  the  thick  parts  are  more  than  twice  as  thick  as  the  average  of 


PENNSYLVANIAN    SYSTEM  45 

No.  2  coal.  The  strata  accompanying  the  coal  in  Aux  Sable  Township^-  and 
in  Goose  Lake  are  not  like  those  typically  associated  with  No.  2  bed.  And 
furthermore,  a  bed  of  limited  extent  lying  20  feet  below  the  level  of  No.  2 
coal  was  mined  at  Jugtown  at  an  early  day. 

4.  Even  if  the  Goose  Lake  coal  be  assigned  to  the  horizon  of  No.  2 
coal,  the  75  feet  of  beds  underlying  it  are  thus  automatically  classed  as 
Pottsville. 

The  thickness  of  the  Pottsville  ranges  from  a  few  feet  at  the  north  edge 
of  the  Pottsville  belt  to  about  90  feet  northeast  of  Morris.  South  of  the 
Illinois  records  of  but  few  borings  penetrating  beds  below  the  Pottsville  are 
available  and  these  show  from  33  to  75  feet  of  Pottsville  present.  North  of 
the  river  19  available  logs  show  Pottsville  thicknesses  ranging  from  10  to  89 
feet.  In  general  the  formation  is  thinner  at  the  west  margin  of  the  quad- 
rangle, thicker  toward  the  southeast,  but  in  all  cases  thins  toward  the  out- 
crop. The  surface  of  the  Pottsville  ranges  in  elevation  from  more  than  500 
feet  above  sea  level  near  the  outcrop  to  454  feet  at  Morris  and  to  a  minimum 
of  376  feet,  two  miles  west  of  Coal  City.  The  details  of  the  relief  of  this  sur- 
face are  not  known  but  there  is  a  general  slope  to  the  top  of  the  Pottsville 
toward  the  south  and  west. 

Lithologically  the  Pottsville  includes  sandstones  and  shales  with  an  incon- 
sequential amount  of  coal  in  thin  and  locally  developed  beds.  There  are 
gradational  types  between  sandstone  and  shale,  as  well  as  calcareous  and 
bituminous  varieties.  Exposures  of  Pottsville  beds  are  mainly  of  sandstone, 
although  the  more  extensive  outcrops  reveal  interbedded  shales,  which  have 
not  sufficient  resistance  to  weathering  to  give  rise  to  independent  outcrops. 
A  good  section,  of  more  than  40  feet,  may  be  constructed  from  a  discontinu- 
ous exposure  on  the  Kankakee  in  section  1  of  Goose  Lake  Township  (T.  33 
N.,R.  8E.)  and  in  adjoining  sections  up  and  down  stream.  The  section 
follows : 

Pottsville  section  exposed  along  Kankakee  River,  Goose  Lake  Township 

Thickness 
Ft.     In. 
Sandstone,  shaly,  thin-bedded  but  including  abundant  sandstone  concre- 
tions       15 

Shale,  gray,  in  part  carbonaceous,  and  black,  with  some  black  plant   frag- 
ments       12 

Sandstone,  light  gray,  coarse  grained,  including  a  gray  to  black  shale  with 

abundant  plant  fragments 4 

Shale,  dark  brown,  weathering  yellow  and  pink 1       6 

Clay,  light  greenish  gray,  bedding  marked  by  prominently  jointed  resistant 
calcareous  lenses 12 

46       6 


"Bradley,  Frank  H.,  Geol.  Survey  of  Illinois,  Vol.  IV,  p.  198.  1870. 


46 


GEOLOGY    OF    MORRIS    QUADRANGLE 


There  is  an  exposure  of  beds  probably  below  these  and  possibly  well 
toward  the  base  of  the  Pottsville  on  Aux  Sable  Creek,  where  crossed  by  the 
Illinois-Michigan  Canal.  The  sandstone  here  is  gray,  medium  coarse  in  tex- 
ture, and  composed  essentially  of  quartz  with  a  sprinkling  of  a  black  mineral 
and  fewer  red  and  light-green  grains.  Mainly  finely  laminated  with  excel- 
lent ripple  marks,  some  of  the  strata  are  more  massive,  in  which  case  fine, 
short,  carbonaceous  streakings  are  common.     Some  beds  are  sparsely  fos- 


Fig.   23.     Spherical  concretion   in  sandstone  on   Aux  Sable   Creek 


sihferous.  A  striking  feature  is  the  presence  of  large  sandstone'  concretions 
showing  prominent  cross-bedding,  such  as  were  noted  at  the  Kankakee 
(fig.  23). 

One  of  the  local  carbonaceous  phases,  not  rare  in  the  Pottsville,  is  shown 
in  exceptional  thickness  in  the  clay  pit  of  the  Haeger  Brick  and  Tile  Com- 
pany at  Goose  Lake  (fig.  24)  where  the  following  section  appears: 

Section  of  strata  in  clay  pit  of  the  Haeger  Brick  and  Tile  Company  at  Goose  Lake 

Thickness 
Ft.     In. 

Black  swamp  beds 3       0 

Coal 1  ft.  6  in. 

Clay 9  in. 

Coal 2  ft.  0  in. 

Clay 10  in.  I 

Coal 6  in.j 

"Soapstone",  thickness  ^'ariable 4       0 

Sandstone,  lenticular 2       6 

"Soapstone",  thickness  variable 0       4 

Clay,  base  concealed ^       0 


15 


PF.  N  N'  S  \'  L\-  A  X I A  X    S  V  STE  M 


47 


The  same  or  similar  coal  has  heen  dug  al)out  200  yards  to  the  southeast 
but  there  is  no  indication  that  either  coal  extends  over  more  than  a  tew  acres. 

That  the  Pennsylvanian  system  formerly  extended  farther  north  than 
its  present  limit  in  the  Morris  area  is  suggested  by  the  fact  that  near  its 
present  margin  the  upper  portion  has  been  removed  by  erosion.  This  is  true 
not  only  of  the  beds  above  No.  2  coal  but  of  the  beds  assigned  to  the  Potts- 
ville  as  well.     The  earlier  extension  is  further  indicated  bv  the  fact  that  in 


KiK-  --!•      PrnnssK  Lillian 


|.it  al  llif  \vr>L  i-iul  ut  C 


small  areas  the  present  surface  of  the  strata  shows  considerable  variation  in 
elevation.  For  example,  in  section  34  of  Aux  Sable  Township,  sandstone 
appears  above  the  520-foot  level  while  the  elevation  of  the  surface  for  two 
miles  north  is  below  520  feet.  It  is  obviously  i)robable  that  the  lower  land 
to  the  north  was  originally  covered  by  beds  contemporaneous  with  the  520- 
foot  sandstone.  In  view  of  the  fact  that  the  surficial  material  extends  down 
to  or  below  the  520-foot  level  for  at  least  four  miles  north  of  the  sandstone 
exposure  it  is  evident  that  the  Lower  Pennsylvanian  beds  may  have  extended 
that  far. 

Well  records  in  the  region  are  interesting  in  this  connection.  .V  well 
in  the  SW.  >4  section  22,  Aux  Sable  Township  (T.  34  N.,  R.  8  E. ),  showed 
6  feet  of  "soapstone"  above  the  Macjuokcta  limestone,  which  was  at  503  feet 
above  sea  level.  Wells  in  section  24  show  the  limestone  surface  nearly  50 
feet  lower,  suggesting  that  the  Pennsylvanian  may  have  been  at  least  that 
thick  in  this  area.  \\'ells  in  sections  14  and  9  of  the  same  township  showed 
the  surface  of  the  Maquoketa  limestone  to  rise  northward,  but  fragments  of 
clean  bright  coal  in  drill  cuttings  from  a  well  in  the  NE.  yi  section  9  prove 
the  presence  of  Pennsylvanian  beds  at  that  point.  Three  miles  north  of  the 
Morris  quadrangle  in  section  3  of  Seward  Township  (  T.  3d  N.,  R.  8  E.), 
Kendall  County,  four  feet  of  coal  is  reported  from  a  dug  well  beneath  21 


48 


GEOLOGY    OF    MORRIS    QUADRANGLE 


feet  of  j;lacial  drift.  This  still  t'uriher  extends  the  limit  of  former  Pennsyl- 
vanian  covering  on  Onloviciaii  rocks.  While  well  records  indicate  the  former 
continuitv  of  Pennsylvanian  beds  over  the  area  immediately  north  of  the 
present  boundary,  it  is  not  clear  that  the  Kendall  County  coal-bearing  beds 


Fig.   2.^.     E.xposurcs  of  Carbondale  beds  along   Mazon   River  near  Tieders  Ford.     The 
lower  is  a  near  view  of  the  distant  beds  shown  above 


were  connected  with  these  by  a  farther  northward  extension,  although  that 
is  the  logical  jxisition  for  the  connecting  link. 

The  stratigraphic  position  of  the  beds  forming  these  outliers  to  the 
Pennsylvanian  area  cannot  be  fixed.  The  scantiness  of  the  lithologic  data 
and  the  lack  of  anv  fossils  make  exact  determination  impracticable. 


PENXSYLVAXIAN    SYSTEM 


49 


CARBONDALE  FORMATION 


Beds  of  Carbondale  age  underlie  the  drift  over  all  of  the  Morris  quad- 
rangle south  of  the  belt  assigned  to  the  Pottsville.  Exposures  are  limited 
to  the  deeper  stream  channels  and  hence  are  infrequently  seen  north  of  Illi- 


Fig.  26.     Typical  exposures  of  Carbondale  strata  on  Mazon  River 

A.  Massive  sandstone  at  Pine  Bluff  Bridge 

B.  Thin  bedded  sandstone  in  sec.  19,  Felix  Twp. 

nois  River.  Nearly  20  feet  of  these  strata  (nitcrop  along  East  Fork  of  Xettle 
Creek  in  the  northwest  part  of  Morris,  and  a  similar  exposure  appears  along 
Xettle  Creek  in  sections  6  and  7  of  Erienna  Township  (T.  33  N.,  R.  7  E.). 
No  outcrops  appear  in  the  channel  of  the  Illinois,  but  south  of  the  river  the 
Pennsylvanian  beds  appear  interruptedly  akmg  Waupecan  Creek  and  Mazon 


50 


GEOLOGY    OF    MORRIS    QUADRANGLE 


River.     (See  fig.  25.)     The  latter  group  of  exposures  comprises  the  larger 
section  and  includes  all  beds  outcropping  on  Waupecan  Creek. 

In  general  the  Carbondale  strata  are  uniform  over  wider  areas  than  are 
the  Pottsville  beds,  as  indicated  by  the  widespread  continuity  of  the  basal 


J.U 

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Fig.  27.     Waupecan  sandstone  and  underlying  beds  on  Waupecan  Creek.     The  contact 
is  marked  by  the  undercutting  below  the  massive  sandstone. 


member,  No.  2  coal.  Above  the  coal  lies  a  variable  thickness  of  shale,  sandy 
shale,  and  shaly  sandstone  with  but  little  pure  sandstone  and  almost  no  lime- 
stone. In  the  latter  feature  it  ditTers  markedly  from  the  typical  McLeans- 
boro  in  which  calcareous  beds  are  prominent.  The  thickness  of  the  Carbon- 
dale  varies  from  10  feet  at  the  northeastern  margin  to  about  150  feet  in  the 
deeper  parts  of  the  basin.     This  variation  is  due  to  a  combination  of  factors. 


PENNSYLVANIAN    SYSTEM 


51 


the  two  most  important  being  dilTerences  in  original  thickness  and  in  the 
amount  of  subsequent  erosion.  A  difference  in  the  elevation  of  the  surface 
of  No.  2  coal  of  about  50  feet  occurs  two  miles  west  of  Coal  City.  This  has 
been  interpreted  as  a  synclinal  structure/^  but  may  possibly  be  explained  as 
an  original  inequality  in  the  surface  of  the  basin  of  deposition,  since  the  coal 
here  is  more  than  30  inches  thicker  than  outside  of  the  trough.  In  any  event 
it  causes  a  corresponding  difference  in  thickness  of  the  formation.  Similar 
but  less  marked  relief  in  the  surface  of  No.  2  coal  with  corresponding  varia- 
tion in  the  thickness  of  the  overlying  beds  occurs  in  the  vicinity  of  Morris. 


Fig. 


28.     Exposure  showing  beds  below  Waupecan  sandstone;  the  shales  bearing  nodular 
limestone  are  at  the  water's  edge.     Mazon  River,  sec.  6,  Maine  Twp. 


Although  uniform  in  their  general  characters,  the  exposures  of  these 
rocks  reveal  marked  lithologic  differences.  These  are  in  part  differences 
between  different  parts  of  the  formation  and  possibly  in  part  differences  in 
phases  of  the  same  beds.  Thus  the  section  at  Pine  Bluff  Bridge  shows  rela- 
tively massive  beds  of  cross-bedded  sandstone  (fig.  26).  An  equally  thick 
section  a  few  miles  upstream,  as  in  section  19  of  Felix  Township  (T.  33  N., 
R.  8  E.),  shows  only  shales  and  sandy  shales.  Another  exposure  may  reveal 
sandstone  underlain  by  gray  shales,  black  fissile  shale  or  in  places  a  thin  coal 
bed.  Similar  but  less  marked  differences  appear  in  what  seems  to  be  the 
same  part  of  the  formation.  Thus  the  plastic  shales  including  the  fossil  beds 
of  section  13,  Wauponsee  Township  (T.  33  N.,  R.  7  E.),  are  distinctly  sandy 
in  the  upstream  portion  in  section  24,  so  that  although  apparently  belonging 
in  the  same  stratigraphic  zone  the  two  sections  are  lithologically  distinct. 

The  details  of  the  stratigraphy  of  the  Carbondale  formation  are  not 
readily  ascertained  from  even  such  good  exposures  as  lie  along  Mazon  River. 

I'Cady,  G.  H.,  Coal  Resources  of  District  I  (LongwalU:    111.  Coal  Mining  Investigations  Bull.  10,  p.  73, 


52  GEOLOGY    OF    MORRIS    QUADRANGLE 

It  is  impracticable,  therefore,  to  attempt  to  present  a  detailed  section,  although 
a  generalized  column  is  possible  from  present  data.  This  includes  the  fol- 
lowing members : 

Generalized  section  of  Carhondale  fonnntioH  ^,-  , 

Feet 

4.  Sandstone  and  shaly  sandstone 10 — 25 

3.  Shale,  including  carbonaceous  beds 15 — 25 

2.  Sandstone  and  shale 65 — 100 

1.  No.  2  coal  (average) 3 

Evidence  is  fairly  clear  as  to  the  presence  of  at  least  one  break  in  the 
sedimentary  record  of  the  Carhondale  in  this  area.  It  is  at  the  top  of  No.  3 
of  the  above  section  and  is  marked  by  a  distinct  change  in  the  character  of 
deposit  and  possibly  by  an  uneven  contact.  The  base  of  the  sandstone  of 
No.  4  in  many  places  clearly  occupies  an  erosional  depression  in  the  lower 
beds,  but  in  other  places  the  relations  are  by  no  means  clear.     (See  fig.  27.) 

The  section  just  below  this  stratigraphic  break  comprises  the  distinct 
and  easily  recognized  group  of  beds  which  are  listed  below: 

Thickness 
Ft.     In. 
6.     Shale,  black,  weathering  to  a  flaky  incoherent  mass 3 

5.  Shale,  black,  fissile,  with  spherical  pyritic  concretions 2 

4.  Shale,  soft,  bony,  grading  below   to   black   flaky   shales   which   are 

gray  at  base 3 

3.  Sandstone,  black,  coarse,  locally  conglomeratic 1 

2.  Clay,  green,  soft,  plastic,  with  embedded  limestone  masses,  nodular 

or  lenticular 2 

1.     Shale,  gray,  soft,  thin-bedded,  base  concealed 1 

11        1 

Considerable  variation  in  the  thickness  of  the  several  members  is  noted, 
but  the  sequence  appears  to  be  without  essential  variation.  Figure  28  shows 
portions  of  beds  6,  5,  4,  and  2,  No.  3  being  indistinguishable  here.  Portions 
of  the  fissile  shale  show  an  excellent  development  of  cone-in-cone  structure 
and  are  distinctly  calcareous  (fig.  29).  The  contact  of  the  sandstones  with 
the  underlying  shales  is  extremely  irregtilar  as  shown  in  figure  30.  This 
tmevenness  seems  to  be  in  part  dtie  to  erosion  and  in  part  to  the  concretionary 
development  both  in  the  sandstone  and  in  the  fissile  shale. 

This  break  above  No.  3  of  the  preceding  section  has  been  followed 
from  the  vicinity  of  Sulphur  Springs  School  west  and  north  beyond  Seneca, 
but  the  heavy  covering  of  drift  prevents  its  exposure  to  the  southwest.  The 
presence  of  a  similar  section  in  borings  near  Verona  suggests  the  continuity 
of  these  beds  and  the  included  stratigraphic  break  over  an  area  of  at  least 
100  square  miles.  The  limited  zone  of  beds  involved  in  the  break,  however, 
strongly  suggests  a  localization  of  the  controlling  conditions. 


PEN.VSVI.VANIAN    SYSTEM 


53 


Two  members  of  the  Carbondale  are  thus  recognized.  The  lower  com- 
prises No.  2  coal  and  the  overlying  sandstone  and  shale  beds  with  locally- 
developed  coal  at  the  top.  Only  the  upper  portion  of  this  member  outcrops 
along  Mazon  River,  but  drilling  shows  it  to  be  from  80  to  125  feet  thick. 
The  upper  member  includes  sandstone  and  overlying  sandy  shale  to  a  thick- 
ness of  25  feet.  These  beds  are  typically  exposed  along  Waupecan  Creek 
and  appear  also  on  Mazon  River  near  Sulphur  Springs.     It  will  be  called  the 


Fig.  29.     Fissile  sliale  showing  calcareous  phase  with 

cone-in-cone  structure.     Mazon 

River  opposite  Johnny  Run 

Wau.pecan  sandstone  in  this  report.     A  development  of  "millstone"  concre- 
tions is  common  if  not  characteristic  of  this  member  (fig.  31). 

By  definition  the  top  of  the  Carbondale  is  marked  by  No.  6  coal,  which 
is  recognized  by  the  overlying  limestone  stratum.  In  the  Morris  area,  how- 
ever, neither  the  coal  nor  the  limestone  marker  of  that  horizon  is  present, 
and  consequently  the  stratigra])hic  position  of  the  upper  beds  of  the  forma- 
tion as  exposed  in  this  quadrangle  is  somewhat  in  doubt.  If  No.  6  coal  was 
ever  laid  down  in  this  region  it  apparently  has  been  removed  by  erosion. 


54 


GEOLOGY   OF    MORRIS    QUADRANGLE 


Consequently  the  present  top  of  the  Carbondale  section  presumably  lies 
stratigraphically  below  the  horizon  of  No.  6  coal. 

Although  the  Waupecan  sandstone  may  belong  to  the  Carbondale,  as 
stated  above,  in  the  absence  of  a  definite  marker  for  the  top  of  that  series, 
it  may  also  be  considered  to  represent  the  McLeansboro  in  this  region.  It  is 
clear  that  the  correlation  of  these  strata  depends  upon  the  correlation  of  the 
included  coal  beds. 

As  already  noted,  No.  2  coal,  the  base  of  the  Carbondale  formation,  is 
remarkably  uniform  in  thickness  and  character  over  wide  areas.  It  is  readily 
recognized  by  drillers  and  serves  as  a  reliable  guide  in  all  stratigraphic  studies 


Fig.  30.     Uneven  contact  of  Waupecan  sandstone  with  underlying  shales,   Mazon  River 
opposite  Johnny  Run 


of  the  region.  In  the  southwest  part  of  the  quadrangle  another  bed  of  coal 
is  found  from  60  to  80  feet  above  No.  2.  This  coal  bed  outcrops  in  Mazon 
River  at  Tieders  Ford  in  section  36  of  Wauponsee  Township  (T.  33  N.,  R. 
7  E.),  and  in  section  6  of  Maine  Township,  at  Sulphur  Springs.  A  coal  bed 
at  this  horizon  also  comes  to  the  surface  on  Waupecan  Creek  in  the  SE.  % 
section  20  of  Wauponsee  Township  (T.  33  N.,  R.  7  E.),  where  it  was  worked 
at  an  early  date,  but  not  much  coal  was  removed.  In  the  latter  place  it  was 
classed  by  Bradley^"*  as  No.  4  seam  of  the  Illinois  section,  while  at  Sulphur 
Springs  outcrop  it  is  commonly  classed  as  No.  7  coal  by  drillers  and  others. 
The  latter  correlation  is  based  on  similarity  of  lithology  and  stratigraphic  se- 
quence of  this  section  with  that  near  Cardifif  where  a  bed  about  60  feet  above 
No.  2  has  been  called  No.  7.  The  fact  that  there  is  considerable  uncertainty  in 
regard  to  the  validity  of  the  correlation  at  Cardiff  lends  doubt  to  the  feasibil- 
ity of  extending  it  farther  west  where  the  relations  are  still  more  obscure. 

"Bradley,  Frank  H.,  Geol.  Surv.  111.,  Vol.  IV,  p.  194,  1870. 


PENNSYLVANIAN    SYSTEM 


55 


However,  if  this  coal  is  No.  7,  then  the  Waupecan  sandstone  belongs  within 
the  McLeansboro.  The  Waupecan  sandstone,  on  the  other  hand,  can  be  traced 
along  its  outcrop  northwestward  nearly  to  Marseilles.  It  has  the  lithologic 
character  and   apparently  the   position   of   the   Vermilionville   sandstone   of 


Fig.  .51.     "Millstone"  concretions  of  Waupecan  sandstone 

A.  In  place 

B.  Dislodged  by  undercutting  in  shale 


Cady,^'"^  which  he  finds  overlying  an  erosion  surface  within  the  Carbondale 
at  about  the  horizon  of  No.  5  coal.  In  fact,  there  seems  little  doubt  but  that 
the   Waupecan   and   the    Vermilionville    sandstones   were    contemporaneous. 


I'Cadv,  G.  H.,  Geology  and  mineral  resources  of  the  Hennepin  and  La  Salle  quadrangles:    111.  State 
Geol.  Survey  Bull.  37,  p.  .S7,  1919. 


56  GEOLOGY    OF    MORRIS    QUADRANGLE 

The  correlation  of  the  Sulphur  Springs  coal  with  No.  7  of  the  Illinois  sec- 
tion appears  unwarranted  and  its  assignment  to  a  position  between  No.  2  and 
No.  5  coals  is  more  in  harmony  with  the  data  at  hand.  On  this  correlation 
all  beds  in  the  Morris  area  above  No.  2  coal  belong  to  the  Carbondale.  It 
must  be  remembered,  however,  that  the  coal  bed  in  question  is  only  locally 
developed  and  shows  marked  variation  in  thickness  so  that  positive  correla- 
tion can  not  be  made  at  the  present  time. 

In  one  boring  in  section  14  of  Braceville  of  Braceville  Township  (  T.  32 
N.,  R.  8  E.),  a  thin  bed  of  coal  was  found  about  20  feet  above  No.  2  coal. 
This  lies  between  No.  2  and  the  bed  which  has  been  called  No.  7.  This  bed 
has  not  been  recognized  in  any  other  log  from  the  Morris  quadrangle,  and 
may  fairly  be  regarded  as  a  northern  extension  of  one  of  the  lower  beds  of 
the  Cardiff  field. 

One  other  formation  in  this  Carbondale  section  is  worthy  of  more  than 
passing  mention.  The  fossiliferous  shales  of  Mazon  River,  from  the  great 
variety  of  forms  as  well  as  the  perfection  of  their  preservation,  have  become 
famous  among  paleontologists  and  collectors  generally. 

These  beds  are  exposed  prominently  in  the  banks  of  blazon  River  at 
two  localities.  The  first  is  along  the  north-trending  part  of  the  stream,  in  the 
SE.  %  section  13  of  \\'auponsee  Township  ( T.  Zi  N.,  R.  7  E. )  ;  the  second 
is  about  two  miles  upstream  just  above  the  sharp  bend  in  the  SE.  \^  NW.  J4 
sertion  30,  Felix  Township  (T.  33  N.,  R.  8  E.). 

These  beds  are  shales,  niainlv  without  grit,  although  somewhat  sandy  in 
places.  They  are  gray,  becoming  brown  and  plastic  on  weathering.  They 
are  finely  laminated  and  in  most  places  cut  by  many  intersecting  joint  planes. 
The  striking  lithologic  feature  is  the  presence  of  great  numbers  of  brown- 
coated  ironstone  concretions.  These  are  of  varied  shape,  but  invariably  have 
the  shortest  diameter  normal  to  the  bedding  planes.  Although  one  or  two 
la}-ers  are  to  be  noted,  the  concretions  show  almost  no  regularity  of  disposi- 
tion, appearing  irregularly  throughout  the  beds.  Within  the  concretions,  but 
not  elsewhere  in  the  formation,  are  the  organic  remains  for  which  these 
beds  are  noted.  Without  apparent  exception  the  concretions  enclose  some 
organic  matter,  such  as  a  bit  of  plant  or  shell,  and  in  some  instances  a  whole 
leaf  is  found.  ^luch  more  rare  are  the  concretions  containing  a  whole  insect 
or  fish  skeleton.  The  perseverance  of  the  collectors  is  indicated  by  the  fact 
that  nearly  a  score  of  species  of  cockroaches  have  been  named  from  speci- 
mens found  here.  The  fossils  thus  formed  show  remarkably  perfect  preser- 
vation, so  that  examination  and  classification  are  greatly  simplified.  The 
concretions  show  bedding  planes  running  through  them,  along  which  they  are 
usually  readily  broken.  In  fact,  the  failure  of  an  experienced  collector  to 
break  a  concretion  cleanly  through  the  middle  is  commonly  taken  as  indica- 
tion that  the  concretion  is  without  a  well-preser\'ed  fossil. 


PLEISTOCENE   SYSTEM 


Pleistocene  System 


57 


That  the  reader  may  have  a  j^roper  understancHng  of  the  references  to 
early  Pleistocene  history  in  the  following  discussion,  it  is  necessary  that  he 
bear  in  mind  the  complex  nature  of  the  glacial  history  of  the  region.  An 
examination  of  the  deposits  of  the  United  States  shows  that  there  have  been 
no  less  than  13  recognizable  stages  and  sub-stages  in  the  time  which  is  called 
the  Glacial  period.  For  convenience,  these  subdivisions,  numbered  in  the 
order  of  their  age,  are  listed  in  talnilar  form  : 

No.  XIII.  The  Champlain  sub-stage  (marine) 

No.  XII."  The  Glacio-laciistrine  sul^-^tage 

No.  XI."  The  Later  Wisconsin  (tue  sixth  advance) 

No.  X.  A  deglaciation  interval  (not  named) 

No.  IX.  The  Earlier  Wisconsin  (the  fifth  advance) 

No.  VIII.  The  Peorian  (the  fourth  interglacial  interval) 

No.  VII.  The  lowan  (the  fourth  invasion) 

No.  VI.  The  Sangamon  (the  third  interglacial  interval) 

No.  V.  The  Illinoian  (the  third  invasion) 

No.  IV.  The  Yarmouth  (the  second  interglacial  interval) 

No.  III.  The  Kansan  (the  second  invasion) 

No.  II.  The  Aftonian  (the  first  known  interglacial  interval) 

No.  I.  The  Nebraskan  (the  earliest  known  ice  invasion) 
«  Represented  in  Morris  Quadrangle. 

It  should  be  recognized  that  these  stages  represent  intervals  of  time 
which  were  by  no  means  equal,  the  earlier  ones  being  markedly  longer  than 
the  later  ones.  Furthermore,  because  the  Wisconsin  ice  sheet  was  the  last 
of  the  ice  invasions,  it  is  possible  to  distinguish  the  deposits  made  at  dif- 
ferent stages  of  this  advance  and  recession. 

PRE-WISCONSIN    DRIFT 

Although  the  Morris  region  must  have  been  covered  by  the  Illinoian  and 
some  of  the  earlier  ice-sheets  and  hence  presumably  received  more  or  less 
deposit  therefrom,  there  is  scant  evidence  of  any  deposit  of  pre-Wisconsin 
age  now  to  be  found.  A  suggestion  of  the  presence  of  such  early  deposits 
is  found,  however,  in  the  occurrence  of  fragments  of  tree  trunks  in  borings. 
Drilling  has  also  shown  the  rock  surface  below  the  drift  to  be  distinctly 
uneven,  as  though  trenched  by  stream  valleys.  While  not  enough  drilling 
has  been  done  to  define  the  course  of  these  depressions,  it  is  evident  that 
they  are  rather  sharp  and  steep-sided  in  many  places.  Such  depressions, 
especially  if  trending  in  a  northwest-southeast  direction,  would  have  been 
filled  with  the  debris  from  the  earliest  glacier  passing  over  the  region  and  in 
many  instances  probably  would  retain  part  of  this  deposit  to  the  present.  It 
is  thus  clear  that  although  over  most  of  the  quadrangle  the  bed  rock  lies 
relatively  close  to  the  surface,  even  there  the  valleys  which  antedated  the 
Wisconsin  ice-sheet  may  hold  remnants  of  an  earlier  glacial  deposit. 


58  GEOLOGY    OF    MORRIS    QUADRANGLE 

C 

WISCONSIN  DRIFT 

Beginning  with  the  oldest,  the  more  important  drift  deposits  of  the 
Wisconsin  epoch  are  known  as  the  Shelbyville,  Champaign,  Bloomington, 
Marseilles,  Minooka,  Valparaiso,  and  Lake  Border  drift  sheets.  The  above- 
named  drift  deposits  comprise  those  of  both  the  Early  and  Late  Wisconsin 
ice.  Late  Wisconsin  time,  as  now  classified,  began  with  the  advance  of  either 
the  Marseilles  or  Minooka  ice-sheets,  but  the  evidence  for  the  separation  of 
the  Early  Wisconsin  and  Late  Wisconsin  deposits  is  not  clear. 

BLOOMINGTON    DEPOSITS 

Of  the  several  drift  sheets  of  Wisconsin  age,  none  earlier  than  the 
Bloomington  is  known  to  be  present  in  the  Morris  region.  In  fact,  Bloom- 
ington till  has  not  been  recognized  within  the  quadrangle,  although  it  is  found 
in  considerable  thickness  less  than  four  miles  west  in  the  valley  of  Hog  Run 
in  section  29,  Norman  Township  (T.  S3  N.,  R.  6  E.).  Where  known,  the 
Bloomington  till  in  this  region  lies  beneath  the  Marseilles  drift.  If  restricted 
to  this  position,  as  seems  likely  because  of  the  thin  drift  cover  over  most  of 
the  area,  it  will  be  found  only  in  the  southwestern  part  of  the  Morris  quad- 
rangle, perhaps  only  west  of  Waupecan  Creek.  In  this  area  most  of  the 
streams  have  not  yet  cut  deeply  enough  to  disclose  any  pre-Marseilles  drift. 
Careful  search  along  Bills  Run,  which  has  a  steep-sided  valley  60  feet  deep, 
failed  to  reveal  any  drift  not  evidently  of  Marseilles  age.  Bloomington  till 
may  be  present,  but  if  so,  is  concealed  by  slope-wash  or  vegetation. 

Like  all  such  deposits,  Bloomington  till  is  gritty,  and  carries  numerous 
boulders.  It  is  distinguished  readily  from  the  overlying  gray  Marseilles 
till  by  its  pinkish  color,  and  in  almost  all  exposures  it  is  more  compact  than 
the  later  till.  As  found  in  Hog  Run,  the  exposure  nearest  the  Morris  area, 
this  till  is  about  20  feet  thick  and  in  the  region  just  west  of  Waupecan  Creek 
it  is  presumably  somewhat  thinner. 

Lacustrine  clays. — Overlying  the  Bloomington  till  is  a  thin  series  of 
sands,  gravels,  and  lacustrine  clays  of  pre-Marseilles  age.  While  neither 
the  lower  till  nor  the  gravels  is  found  within  the  Morris  quadrangle,  lacus- 
trine clays  are  found  (1)  in  the  valley  of  the  East  Fork  of  Nettle  Creek  in 
the  NE.  %  section  4  of  Morris  Township  (T.  33  N.,  R.  7  E.),  (2)  along 
the  town-line  road  at  the  north  line  of  section  4,  and  (3)  about  300  yards  to 
the  north  in  a  creek  bank  (PI.  II).  The  elevation  of  these  clays  is  just 
under  520  feet  above  sea  level,  which  is  approximately  the  elevation  of  the 
lower  part  of  the  ten  feet  of  clays  found  over  sands,  gravels,  and  Blooming- 
ton till  seven  miles  to  the  west,  along  Carson  Creek  in  the  NW.  %  section  17, 
Erienna  Township  (T.  33  N.,  R.  7  E.).  In  character  the  Morris  clays  are 
identical  with  those  on  Carson  Creek  and  hence  they  are  believed  to  repre- 
sent remnants  of  the  same  widespread  lake  deposit. 


PLEISTOCENE    SYSTEM 


59 


The  clays  are  finely  laminated,  and  of  various  colors,  brown,  chocolate, 
pink,  green,  gray,  and  yellow.  The  yellow  beds  are  mostly  sandy,  but  the 
clays  on  the  whole  are  not  gritty.  The  laminations  are  slightly  uneven  in 
all  parts  of  the  deposit  and  in  places  are  extremely  irregular  in  thickness  and 
extent.  This  is  particularly  true  of  the  thin  sandy  phases  which  are  inter- 
bedded  with  the  clays.  In  no  case  was  a  sandy  phase  found  to  extend  hori- 
zontally more  than  two  or  three  feet,  and  in  most  cases  less  than  one. 

The  greatest  exposed  thickness  of  these  clays  is  less  than  20  feet.  A  well 
at  the  tile  plant  at  Morris  records  34  feet  of  clay,  but  since  a  streak  of  coaly 
matter  was  encountered  at  about  20  feet  and  a  fragment  of  well-preserved 
wood  was  found,  it  is  possible  that  the  lower  10  or  15  feet  of  the  "clay" 
may  be  Bloomington  or  some  older  till.  The  relation  of  this  deposit  to  the 
underlying   Pennsylvanian   strata   suggests   its   history.      The   excavation  of 


mMmMmmm&m 


~— -  Lake  beds 


'^'  -' 


30  ft. 


Fig.  32.     Section  of  lake  clays  beneath  till,  exposed  on  south  line  of  sec.  3.?, 
Saratoga  Township 

the  clay  pit  shows  the  clays  to  have  been  deposited  in  a  sharp  depression  in 
the  sandstone  which  practically  surrounds  them.  The  clays  were  clearly 
overridden  by  the  ice  of  the  Marseilles  stage,  but  were  protected  from 
removal  by  the  walls  of  sandstone  on  all  sides. 

The  outcrop  along  the  town-line  road  shows  clearly  the  position  of 
these  clays  beneath  Marseilles  till  (fig.  32),  as  is  indicated  by  their  relations 
in  the  clay  pit  in  section  4.  Their  age,  therefore,  is  post-Bloomington  and 
pre-Marseilles.  This  determination  is  at  variance  with  that  of  Sauer  who 
considered  the  overlying  till  to  be  post-Marseilles  in  age.^"  Without  doubt 
these  clays  were  laid  down  in  a  lake  whose  surface  was  more  than  530  feet 
above  sea  level.  Its  upper  limit  is  not  known  from  exposures  within  this 
quadrangle.  The  extent  of  the  lake  is  likewise  not  known  further  than  tliat 
it  reached  from  Morris  to  Seneca  along  the  site  of  the  Illinois  valley. 


MARSEILLES   DEPOSITS 

The  next  younger  deposit  is  that  made  during  the  Marseilles  sub-stage. 
At  this  time  the  ice  built  the  prominent  ridge  which  extends  in  a  general 
north-south  direction  from  Marseilles.  The  western  boundary  of  the  Mor- 
ris  quadrangle   coincides   approximately    with   the   eastern    margin    of    this 


"Sauer,  C.  C,  Geography  of  the  Upper  Illinois  Valley:    111.  State  Geol.  Survey  Bull.  27,  1916. 


60  GEOLOGY    OF    MORRIS   QUADRANGLE 

morainic  ridge,  which  marks  the  western  edge  of  the  depression  known  as 
the  Morris  basin.  East  of  this  ridge  the  ground  moraine  of  the  same  ice- 
sheet  appears  at  the  surface  except  where  it  has  been  removed  or  concealed 
beneath  later  deposits.  Erosion  has  nearly  or  quite  removed  this  ground 
moraine  from  a  belt  two  to  seven  miles  wide  along  the  present  Illinois  val- 
ley, and  where  not  removed  within  this  belt,  it  has  been  covered  by  later 
deposits.    JMinooka  Ridge,  too,  is  of  younger  drift  and  conceals  the  older. 

The  ground  moraine  of  this  region  is  typically  blue-gray  boulder  clay, 
which  is  gritty  and  hard  when  dry  but  plastic  and  sticky  when  wet.  The 
till  is  massive  and  in  stream  blufifs  and  road  cuts  frequently  stands  in  nearly 
vertical  walls.  The  included  boulders  are  of  many  kinds.  The  resistant, 
well-rounded  boulders  of  crystalline  rocks,  both  igneous  and  metamorphic, 
are  less  abundant  than  those  of  limestone  which  have  more  or  less  angular 
shapes.  The  sandstone  and  shale  which  the  glacier  must  have  picked  up  in 
passing  over  the  Pennsylvanian  terrane  were  apparently  not  able  to  with- 
stand the  grinding  of  glacial  operations  and  were  reduced  to  sand  and  clay 
particles  which  help  to  make  up  the  matrix  of  the  till.  In  places  the  sandy 
material  predominates  and  not  infrequently  a  cut  or  boring  shows  the  pres- 
ence of  considerable  quantities  of  an  ill-assorted  mixture  of  clay,  sand  and 
gravel. 

On  weathering,  the  till  changes  color,  the  blue  giving  place  to  buff  and 
brown.  At  the  same  time  it  loses  its  content  of  calcium  carbonate,  and 
breaks  down  to  a  relatively  incoherent  mass,  ^^'eathering  progresses  un- 
evenly, the  rate  being  controlled  by  the  topographic  position  of  the  till,  its 
porosity,  composition,  and  other  related  factors.  Auger  borings  show  that 
leaching  of  the  calcium  carbonate  and  other  changes  of  weathering  have 
reached  a  depth  ranging  from  20  to  48  inches,  averaging  about  24  inches 
for  the  level  till  surface.  The  greater  depth  to  the  unleached  till  in  places 
results  from  the  superposition  of  a  loess-like  deposit  which  may  be  more 
than  20  inches  thick.  This  was  originally  either  of  leached  or  readily 
leached  material,  and  hence  is  not  to  be  confused  with  the  true  till  in  esti- 
mating the  depth  to  which  leaching  has  occurred.  In  places,  a  more  sandy 
till  shows  incomplete  leaching  to  greater  depths,  more  than  120  inches  being 
recorded  for  a  boring  on  section  19  of  Saratoga  Township. 

The  Marseilles  drift  shows  marked  variation  in  thickness.  The  irreg- 
ularity of  the  surface  on  which  it  was  deposited  is  a  factor  in  producing 
the  variations  in  thickness.  In  general  the  drift  covering  is  thin  in  the 
vicinity  of  Lisbon,  in  the  Aux  Sable  valley,  and  along  the  Illinois  valley, 
and  thicker  in  the  southwestern  part  of  the  quadrangle.  In  the  latter  area 
it  averages  about  60  feet,  while  at  the  northwest  it  feathers  out  to  a  veneer 
of  a  few  inches.  Notable  variations  in  this  thickness  are  found  which  in 
places  suggest  the  presence  of  pre-Marseilles  depressions  of  stream  origin. 


PLEISTOCENE   SYSTEM 


61 


Fig.  33.    Map  of  Morris  Quadrangle  showing  contours  on  bed  rock  surface 


62  GEOLOGY    OF    MORRIS    QUADRANGLE 

Although  in  part  developed  by  post-glacial  erosion,  the  present  bed-rock  sur- 
face, where  covered  by  till,  is  believed  to  be  essentially  the  same  as  that  of 
pre-Marseilles  time.  On  figure  33  are  presented  contours,  based  on  well 
records  and  outcrops,  showing  the  present  bed-rock  surface. 

Topographically,  the  drift  sheet  of  Marseilles  age  in  this  quadrangle  has 
a  distinctly  subdued  expression  which  apparently  is  original.  Certain  knolls 
and  ridges  appear,  but  these  are  prominent  by  reason  of  their  rarity  and 
serve  to  emphasize  the  monotonous  topography  of  the  region  as  a  whole. 
Among  these  elevations  are  to  be  noted  a  low,  uneven-topped  ridge  trending 
northeast  across  the  extreme  northwest  part  of  Saratoga  Township  and  the 
adjacent  territory.  This  is  little  more  than  a  row  of  elongated  knolls  which 
uniformly  show  slightly  worn  and  poorly  assorted  sand  and  gravel  on  the 
northwest  side  and  are  apparently  correctly  interpreted  as  kame-like  deposits 
made  when  the  edge  of  the  retreating  ice  stopped  at  that  position  for  a  short 
time.  These  lie  above  the  620-foot  level  in  part,  and  in  part  between  600 
and  620  feet. 

Another  ridge,  more  prominent  topographically,  is  in  section  13  of 
Saratoga  Township.  This  is  about  20  feet  above  the  adjacent  surface  and 
appears  to  be  a  till  ridge  without  sand  or  gravel  on  top,  although  a  drill 
record  from  its  west  end  shows  41  feet  of  "surface,"  probably  till,  with  15 
feet  of  sand  beneath  and  with  15  feet  of  hard  pan  between  the  sand  and  the 
underlying  rock  surface.  That  this  is  not  a  rock  hill  with  till  veneer  is  evi- 
dent from  the  fact  that  the  rock  surface  here  is  lower  than  that  of  nearby 
outcrops  of  Ordovician  limestone. 

About  three  miles  west  of  Aux  Sable  Creek  and  trending  parallel  to 
the  course  of  that  stream  is  a  series  of  low-rounded  hills  of  till.  Their  dis- 
tribution and  character  suggest  this  as  the  position  of  the  ice  front  during 
another  halt  in  its  retreat.  They  may  also  be  interpreted  as  the  deposit 
made  by  ice  advancing  farther  than  Minooka  Ridge,  either  before  or  after 
it  was  formed.  The  northernmost  of  this  series  of  hills  appears  in  the  south 
half  of  section  21  of  Seward  Township  (T.  35  N.,  R.  8  E.),  Kendall  County, 
about  a  mile  west  of  Shurtliffe  bridge.  A  small  elevation  appears  just  north 
of  this,  but  whether  it  is  a  part  of  this  series  or  not  is  not  clear.  To  the 
southwest  there  is  a  hill  in  section  29,  another  in  32,  another  in  31,  of  the 
same  township,  and  a  possible  continuation  is  noted  in  a  southwest  projec- 
tion of  the  higher  land  across  the  county  line  in  section  2  of  Saratoga  Town- 
ship ( T.  34  N.,  R.  7  E.).  These  are  all  marked  by  the  580-contour  line.  If 
the  interpretation  of  this  series  as  a  recessional  moraine  is  correct,  the  ice 
front  maintained  a  position  essentially  parallel  to  the  Marseilles  moraine 
during  its  retreat.  This  would  probably  involve  the  continuance  of  the  pro- 
jection of  ice  in  the  valley  of  the  Illinois,  and  this,  in  turn,  would  be  an 
important  factor  in  the  frontal  conditions  south  of  the  valley.     The  ice  in 


PLEISTOCENE    SYSTEM  63 

the  valley  would  serve  as  a  barrier  between  the  waters  north  and  south  of  it, 
and  drainage  conditions  on  either  side  would  be  unrelated. 

MINOOKA    DEPOSITS 

This  deposit,  probably  post-Marseilles  in  age,  lies  mainly  east  of  the 
area  under  investigation,  but  its  west  margin  encroaches  on  the  Morris  area. 
It  covers  the  earlier  deposits  over  the  area  north  of  the  Illinois  and  east  of 
Aux  Sable  Creek.  Minooka  Ridge,  extending  from  Dresden  Heights  north- 
ward beyond  the  limits  of  the  quadrangle,  and  forming  the  northeastern  rim 
of  the  Morris  basin,  is  the  outer  ridge-like  border  of  the  Minooka  drift.  The 
origin  of  the  ridge,  however,  is  not  clearly  indicated  by  its  features  as  within 
the  Morris  quadrangle.  These  include,  (1)  a  slightly  curved  trend,  convex 
westward;  (2)  a  steep  erosion  slope  at  the  south  and  east;  (3)  a  western 
slope,  less  steep  and  not  evidently  developed  by  erosion ;  and  (4)  a  remark- 
ably flat  top  about  two  miles  wide. 

The  prominence  of  the  ridge  as  viewed  from  the  adjacent  lowland, 
although  obviously  due  in  part  to  recent  erosion,  strongly  suggests  a  terminal 
moraine.  The  absence  of  the  usual  topographic  features  of  a  terminal  deposit 
and  the  flat  top,  which  apparently  is  continued  in  the  upland  east  of  the 
Des  Plaines,  favor  an  origin  beneath  the  ice-sheet  rather  than  at  its  edge. 
Possibly  the  available  data  are  best  harmonized  in  the  conclusion  that  Minooka 
Ridge  represents  deposition  under  the  edge  of  the  ice  readvancing  after 
a  recession  from  the  Marseilles  moraine  and  staying  at  its  line  of  maximum 
advance  only  a  short  time.  Inspection  of  the  extension  of  Minooka  Ridge, 
especially  to  the  north,  where  outwash  deposits  have  been  reported,"  may 
yield  conclusive  evidence  on  the  question. 

This  till  is  bluish  or  greenish  gray  in  color,  weathering  to  the  same  buff 
or  light-yellow  colors  assumed  by  the  Marseilles  drift.  In  fact  its  chief  dif- 
ference from  that  drift  is  the  relative  scarcity  of  included  boulders.  No 
section  of  more  than  20  feet  of  this  deposit  has  been  observed,  the  steep 
slopes  of  the  southern  extremity  of  the  ridge  being  so  covered  with  slope 
wash  and  vegetation  as  to  make  observation  there  impracticable  (fig.  13). 
Consequently  neither  the  thickness  nor  the  relation  of  this  till  to  the  under- 
lying material  has  been  determined.  The  few  well  records  at  hand  show  a 
uniform  thickness  of  about  100  feet  for  the  material  above  Ordovician  lime- 
stone at  the  south  end  of  the  ridge  and  about  20  feet  less  at  the  north  end. 
Whether  this  is  largely  or  only  in  small  part  Minooka  till  is  not  known. 

The  relation  of  the  Minooka  ice  to  that  of  the  preceding  Marseilles  and 
of  later  stages  is  not  clearly  shown  by  data  available  in  the  Morris  region. 
Because  of  the  short  time  involved  it  makes  little  difference  whether  the 
Minooka  moraine  be  considered  as  a  recessional  deposit  of  the  waning  Mar- 
seilles ice,  or  as  a  terminal  ridge  developed  during  a  readvance  of  the  ice. 

"Leverett,  Frank,  The  Illinois  glacial  globe,  U.  S.  Geol.  Survey  Mon.  38,  p.  322,  1899. 


64  GEOLOGY    OF    MORRIS    QUADRANGLE 

The  flat  top  of  the  ridge  has  suggested  the  possibiHty  that  an  earher 
ridge,  possibly  of  Marseilles  age,  and  formed  as  a  recessional  moraine  dur- 
ing the  retreat  of  that  glacier,  was  later  overridden  by  readvancing  ice  which, 
however,  went  only  a  few  miles  westward,  stopping  in  the  valley  of  Aux 
Sable  Creek.  The  extraordinary  abundance  of  boulders  in  this  vicinity  has 
been  interpreted  as  the  result  of  deposition  by  this  later  ice/®  No  additional 
evidence  favoring  this  hypothesis  has  been  secured  and  its  retention  appears 
questionable. 

FI,UVL\L     VXD    LACUSTRINE    DEPOSITS 

Overlying  the  glacial  deposits  just  described  are  certain  stream  and  lake 
deposits  related  to  the  later  glacial  history  of  the  region.  These  are  refer- 
able to  certain  stages  in  the  development  of  the  IlHnois  valley,  which  is  now 
occupied  by  a  descendant  of  ice-fed  streams  of  much  greater  volume  and 
power.  Plate  II  shows  the  topographic  relations  of  the  deposits  in  the  Mor- 
ris quadrangle  and  Plate  1 11^  shows  their  general  relations  over  the  whole 
Morris  Basin. 

Of  these  later  deposits  the  oldest  has  a  maximum  elevation  of  about 
560  feet  above  sea  level.  This  is  a  barely  discernible  ridge  of  sand  and  fine 
gravel  at  the  junction  of  the  widespread  plain  above  the  560  level,  with  the 
prominent  flat  some  15  feet  lower.  Associated  with  this  ridge  is  the  silt  cov- 
ering of  the  lower  flat.  The  only  place  in  the  quadrangle  where  these  rela- 
tions are  clear  is  at  Coal  City.  Here  the  slope  separating  the  two  flats  is 
well  marked  and  the  silt  and  sand  deposits  of  the  lower  flat  reach  a  maximum 
thickness  of  more  than  10  feet,  17  feet  being  recorded  in  a  boring  in  section 
26,  Felix  Township.  These  deposits  seem  fairly  interpreted  as  those  of  a 
rather  large  lake  whose  surface  was  about  560  feet  above  sea  level,  and 
whose  waters,  coming  from  the  melting  ice  to  the  east,  were  damned  at  the 
west  by  the  Marseilles  moraine,  perhaps  near  Seneca.  Traced  southward 
nearly  to  Mazon  and  thence  northwestward  to  the  Illinois  along  the  Waupe- 
can  valley,  the  slope  joining  these  two  flats  becomes  inconspicuous,  and  only 
in  places  are  the  above-described  relations  suggested.  Certain  knolls  rising 
above  the  560-foot  level  on  the  east  side  of  Waupecan  Creek  in  section  28  of 
Wauponsee  Township  (T.  33  N.,  R.  7  E.),  suggest  by  the  character  of  their 
surface  material  that  they  may  be  remnants  of  a  bar-like  deposit  related  to 
the  deposits  in  question.  North  of  Illinois  River  the  only  traces  of  any 
beach  deposit  at  this  level  are  those  found  on  the  Nettle  Creek  road,  where 
a  slight  accumulation  of  sand  suggests  that  origin. 

Elsewhere  within  the  quadrangle  below  the  560-foot  level  silt  or  sand 
deposits  are  suggested  in  the  character  of  the  soil  but  the  original  limits  of 
this  type  of  sediment  have  been  altered  by  slope  wash,  wind  action,  and  culti- 
vation, so  that  it  is  no  longer  possible  to  draw  the  boundaries   in  detail. 

«8Leverett,  Frank,  The  Illinois  glacial  globe,  U.  S.  Geol.  Survey  Men.  38,  p.  327,  1899. 


PLEISTOCENE    SYSTEM  65 

Topographic  details  will  be  added  in  the  summary  of  evidence  on  the  exist- 
ence of  this  body  of  water  presented  in  connection  with  the  glacial  history 
of  the  region. 

In  this  connection,  it  is  of  interest  to  note  that  along  the  eastern  margin 
of  the  Morris  basin,  in  Will  County,  there  are  remnants  of  a  fairly  well- 
developed  beach  line  at  the  560-level/''  lliere  are  also  prominent  gravel  and 
sand  deposits  showing  in  places  inclined  bedding  both  south  of  Wilmington 
and  southeast  of  Channahon.  These  apparently  mark  the  mouths  of  heavily 
laden  streams  entering  this  body  of  water. 

Another  group  of  deposits,  still  younger,  is  found  at  about  the  540- foot 
level.  Beach  development  is  much  more  pronounced  at  this  level  than  at  the 
560-foot  level  and  is  traceable  for  miles  on  each  side  of  the  Illinois.     There 


Fig.  34.     Dune  near  east  end  of  Sand  Ridue 

are  no  considerable  deposits  now  recognized  on  the  lower  flat,  however. 
The  beach  has  its  best  development  north  of  the  Illinois,  where  there  is  a 
relatively  steep  slope  joining  the  flat,  wh.ich  has  an  elevation  of  about  525 
feet,  with  the  550-foot  flat  to  the  north.  The  toj)  of  the  slope  is  marked  by 
a  low  ridge  having  a  maximum  width  of  50  feet  and  averaging  2  feet  high. 
The  ridge  is  composed  of  worn  pea  gravel  in  a  sandy  silt  matrix,  wholly 
leached  of  calcium  carbonate.  The  surface  north  of  the  ndgc  is  an  essentially 
level  plain  rising  northward  about  5  feet  to  the  mile.  The  surface  south  of 
the  ridge  is  slightly  undulating  with  swamp  areas  suggesting  channel  scars. 
Boulders  are  abundant  on  this  lower  flat,  whereas  they  are  nearly  absent  on 
the  higher. 

''The  beach  line  may  be  seen  in  sections  1,  2,  and  12,  WilmitiRton  Township,  and  the  sand  and  gravel 
with  delta  bedding  appear  at  the  north  line  of  section  16,  Channahon  Township.  Similar  gravels  are  to  be 
found  in  sections  17  and  35,  same  township,  as  well  as  in  sections  7  and  18  of  Wesley  Township. 


66 


GEOLOGY    OF    MORRIS    QUADRANGLE 


North  of  the  Illinois  from  a  point  near  the  west  boundary  of  the  quad- 
rangle as  shown  on  Plate  II  the  540-foot  contour  line  marks  the  position  of 
this  old  beach,  remnants  of  which  are  readily  seen  on  each  side  of  Nettle 
Creek  and  which  can  be  traced  along  the  Ridge  Road  to  Aux  Sable  Creek. 
East  of  this  creek  the  beach  topography,  if  existent,  has  been  obscured  by 


Fig.  35.    Gravel  pit  in  N.E.34  sec.  33,  Goose  Lake  Twp. 


the  development  of  dunes.  Farther  southeast  beyond  Sand  Ridge,  however, 
the  older  topography  is  still  discernible,  and  the  beach  can  be  followed  across 
the  Elgin,  Joliet  and  Eastern  right-of-way  to  the  steeper  slopes  of  IMinooka 
Ridge  west  of  Dresden  Run.  Here  subsequent  erosion  by  Illinois  River  has 
removed  all  trace  of  the  shore  line. 


PLEISTOCENE    SYSTEM  67 

South  of  Illinois  River  remnants  of  an  old  beach  probably  referable  to 
this  same  body  of  water  are  to  be  seen  on  both  sides  of  Waupecan  Creek. 
From  there  eastward  the  abrupt  slope  with  its  crown  of  gravel  and  sand 
may  be  traced  readily  as  far  as  Mazon  River  (PI.  II).  Beyond  this  point 
all  trace  of  the  slope  separating  the  tw^o  flats  is  lost,  the  surface  showing  a 
nearly  uniform  gradient  from  below  to  an  elevation  above  the  540- foot  level. 
The  wide  expanse  of  wind-blown  sand,  having  its  maximum  development 
in  the  dune  area  north  of  Coal  City,  known  as  Sand  Ridge  (fig.  34),  gives 
a  plausible  reason  for  the  absence  of  the  beach  topography. 

East  of  the  quadrangle,  in  Will  County,  remnants  of  this  beach  line  are 
seen  at  several  points,  notably  in  section  11  of  Wilmington  Township  (T.  33 
N.,  R.  9  E.),  so  that  the  combined  remnants  within  the  Morris  basin  enclose 
fairly  completely  the  area  covered  by  this  body  of  water.  Considering  the 
lack  of  silt  deposits  on  the  lower  flat  and  the  evidences  on  its  surface,  it 


Fig.  36.     View  in  sec.  33  Goose  Lake  Twp.  showing  the  topographic  relation  between  the  present  Illinois 
flood-plain  on  the  left  and  the  earlier  gravel  deposits  on  the  right.    The  500  foot 
contour  marks  the  junction  of  the  two  areas 

appears  questionable  whether  this  body  of  water  of  sinuous  shape  and  some 
20  miles  long  by  5  miles  wide  should  be  called  a  lake.  All  conditions  seem 
satisfied  by  considering  it  to  have  been  a  wide  river  of  low  gradient,  yet 
capable,  because  of  local  expansion  to  great  width,  of  forming  a  prominent 
beach  line.  The  anomalous  feature  of  these  beach  deposits,  the  apparent 
evenness  of  the  beach  itself,  is  not  satisfactorily  explained.  In  the  absence  of 
exact  levels  at  the  top  of  the  beach,  however,  it  is  obvious  that  an  existing 
down  stream  slope  in  the  beach  line  may  not  be  apparent  from  the  topo- 
graphic map. 

At  a  still  lower  level  there  are  found  certain  deposits  which  clearly  are 
of  later  age  and  ditiferent  origin  from  those  previously  described.  These 
include  sands  and  coarse  gravels  which  are   restricted  to  a  comparatively 


68  GEOLOGY    OF    MORRIS    QUADRANGLE 

narrow  area  on  both  sides  of  the  Ilhnois.  They  He  within  a  trench,  mainly 
shallow,  but  locally  apparently  sharp  and  deep.  In  the  next  higher  flat,  the 
junction  of  the  two  surfaces  is  marked  in  places  by  a  5-  to  15-foot  slope. 
They  are  only  found  below  an  elevation  of  about  525  feet  so  that  their  limit 
is  marked  approximately  by  the  520- foot  contour  line.  That  portion  below 
the  500-foot  level  is  in  most  places  covered  by  deposits  of  recent  time.  These 
beds  are  quite  uniform  in  character  and  composition,  and  are  readily  assign- 
able to  a  common  origin,  ^^'hile  not  more  than  20  feet  is  exposed  at  any 
point,  drilling  shows  them  to  range  in  thickness  from  two  or  three  feet  to 
possibly  as  much  as  60  feet,  thus  constituting  an  important  group  of  beds. 
A  typical  exposure  is  that  found  in  a  gravel  pit  about  a  mile  east  of 
Devine  Station  in  the  NE.  ^4  section  33  of  Goose  Lake  Township  (fig.  35). 
The  section  is : 

Pleistocene  gravel  exposed  in  sec.  33  of  Goose  Lake  To-wnship 

Thickness 
Inches 

Soil,  black,  sandy,  with  few  pebbles,  maximum  diameter  Yi  inch 6 

Subsoil,  gray  black,  more  sandy,  pebbles  maximum  diameter  1  inch 3 

Gravel,  dark  gray  brown,  variable  thickness,  average 6 

Sand,  yellow  brown,  the  lower  part  finer,  clean,  with  few  pebbles  of  maxi- 
mum diameter  1  inch,  CaCOs  leached 20 

Gravel,  cross  bedded  in  part,  clean,  average  diameter  of  pebbles  greater 
than  1  inch.    About  50  per  cent  limestone,  the  rest  igneous  and  metamor- 

phic  rocks,  with  some  chert 30 

Sand,  locally  pebbly,  but  mainly  clean,  cross  bedded  in  part  exposed  ...  30 

Similar  beds  of  gravel  and  sand  were  opened  in  the  old  city  gravel  pits 
at  Morris,  just  north  of  the  junction  of  the  main  forks  at  Nettle  Creek. 
Such  deposits  have  been  opened  in  section  29  of  Aux  Sable  Township 
(T.  34  N.,  R.  8  E.),  in  section  16  of  Wauponsee  Township  ( T.  ii  X., 
R.  7  E.),  and  in  scores  of  places  along  the  Illinois.  In  fact,  they  constitute 
the  only  local  source  of  clean  sand  and  gravel  for  this  region.  The  surface 
of  these  deposits  is  slightly  more  uneven  than  that  of  the  525-foot  level, 
and  is  usually  distinguished  by  its  rolling  character  with  bar-like  knolls  and 
ridges  of  sand  and  gravel. 

Overlying  the  gravels  but  clearly  antedating  the  recent  alluvial  deposits 
of  the  main  valley  is  a  small  patch  of  marl  and  peaty  muck  which  appear  to 
belong  to  the  closing  stages  of  this  520-foot  river.  It  seems  probable  that 
these  fresh  water  beds  belong  to  deposits  made  in  the  greatly  expanded  river 
rather  than  in  a  marginal  pond,  but  there  is  nothing  to  indicate  whether  the 
water  was  a  lake  or  river.  In  the  marl  bed.  uncovered  in  Bell's  stripping 
near  Morris,  the  following  shells  are  abimdant :"° 

^oTlie  determination  of  these  shells  was  kindly  made  by  Frank  Collins  Baker  who  offered  the  following 
sugges  ions  as  to  the  environment  they  indicated:  "The  body  of  water  must  have  been  of  considerable  size 
to  have  supported  so  large  a  fauna,  but  it  need  not  have  been  very  deep.  Most  of  the  forms  represented  are 
common  in  water  5-8  feet  deep,  and  a  depth  of  10-20  feet  is  sufficient  for  all  the  species." 


PLEISTOCENE    SYSTEM  69 

Mollusca  from  Pleistocene  in  Grundy  County 

Planorbis  antrosus  Conrad 

Planorbis  antrosus  striatus  Baker 

Planorbis  campanulatus  Say 

Planorbis  deflectiis  Say 

Planorbis  altissimus  Baker 

Planorbis  exacuoiis  Say 

Amnicola  leightoni  Baker 

Amnicola  liistrica  Pilsbry     Variety  (new) 

Amnicola  walkeri  Pilsbry 

Valvata  tricarinata  Say 

Valvata  tricarinata  perconfusa  Walker 

Valvata  tricarinata  infracarinata  Vanatta 

Valvata  tricarinata  simplex  Gould 

Valvata  tricarinata  variety  (new) 

Galba  obrussa  decampi  Streng 

Physa  anatina  Lea 

Physa  walkeri  Crandall 

Pisidium,  several  undetermined  species 

The  relation  of  these  deposits  to  the  eariier  ones,  as  noted  above,  is  one 
of  deposition  within  a  trench  cut  in  the  earHer  flat.  Their  relations  to  later 
deposits  are  less  simple.  The  superposition  of  alluvium  of  the  present  Illi- 
nois River  upon  the  gravels  is  shown  in  the  pit  at  the  ice  house  just  south 
of  the  Illinois-Michigan  Canal  at  Morris.  Here  the  usual  gravels  are  over- 
lain by  about  3  feet  of  black  alluvium  which  is  clearly  continuous  southward 
to  the  river.  In  fact,  the  pit  is  flooded  nearly  every  year.  Similar  relations 
are  seen  in  the  vicinity  of  section  5  of  Goose  Lake  Township  (T.  ?)2)  N., 
R.  8  E.),  where  "islands"  of  sand  and  gravel  projecting  above  the  level  of 
the  floodplain  constitute  prominent  knolls.  These  are  outlined  with  fair 
accuracy  by  the  500-foot  contour  lines   (fig.  36). 

Modification  of  these  relations  through  the  agency  of  the  wind  appears 
in  section  5  of  Goose  Lake  Township,  where  dune  sand  is  heaped  into  an 
east-west  trending  ridge  more  than  ten  feet  above  the  floodplain  of  the  Illi- 
nois. This  is  an  active  dune  area  and  in  its  obliteration  of  the  usual  topo- 
graphic relations  of  the  floodplain  and  the  older  gravel  flat  suggests  the 
mode  of  concealment  of  topographic  forms  at  the  junction  of  the  earlier 
developed  flats  at  higher  levels. 

From  the  composition,  structure,  and  position  of  these  deposits  it  is 
clear  that  they  were  made  by  westward  flowing  streams  of  such  volume  and 
velocity  as  to  be  able  to  transport  considerable  loads  of  relatively  coarse 
sediment.  Practically  no  fine  material  referable  to  this  stage  has  been  found. 
Hence  these  deposits  are  assigned  to  an  early  Illinois  River  of  greater  volume, 
though  possibly  of  lower  gradient  than  the  present  stream. 

Genetically  related  to  the  foregoing  stages  of  development  of  the  pres- 
ent Illinois  valley  there  are  many  deposits,  individually  of  small  extent  but 


70 


GEOLOGY   OF    MORRIS   QUADRANGLE 


rather  large  in  the  aggregate,  which  occupy  slightly  elevated  positions  above 
the  floodplains  of  the  various  tributaries,  past  or  present,  to  the  main  stream. 
These  are  now  terraces  of  coarse  or  fine  materials,  usually  well  stratified 
and  similar  to  the  deposits  of  the  main  stream  (fig.  37).  In  many  instances 
they  can  be  assigned  to  one  or  another  of  these  three  stages  of  Illinois  River 
which  preceded  the  present  stage  on  the  basis  of  their  elevation  and  geo- 
graphic position.     While  it  has  not  been  considered  important  to  map  these 


f^^gf^:^-;-  '32^-f r:5 


Fig. 37.     Terrace  gravels  overlying  fresh  gray  till  in  bank  of  Nettle  Creek  sec.  31,  Saratoga  Twp.     The 
stratified  character  of  the  gravels  and  sand  lenses  serves  to  distinguish  them  from  the 
massive  till  below.     Note  the  unevenness  of  the  till  surface 


terraces  so  as  to  show  their  relations  to  contemporaneous  deposits  made  in 
the  main  valley,  it  may  be  well  to  point  out  localities  in  which  the  various 
terraces  are  well  exhibited.  Nettle  Creek,  in  section  31  of  Saratoga  Town- 
ship (T.  34  N.,  R.  7  E.)  and  southward  in  the  north  part  of  section  6  of 
Erienna  Township  (T.  33  N.,  R.  7  E.),  shows  a  series  of  terraces  from 
3  to  10  feet  high  which  apparently  were  developed  during  the  down-cutting 
of  this  stream  as  the  Illinois  was  lowered  (fig.  38).  Aux  Sable  Creek  and 
its  tributaries,  Collins  and  Walley  runs,  show  such  terrace  remnants  inter- 
ruptedly throughout  most  of  their  valleys  in  Aux  Sable  Township  (T.  34  N., 
R.  8  E.).  Such  deposits  have  furnished  gravels  along  Walley  Run  in  sec- 
tions 7  and  18  of  this  township. 

South  of  Illinois  River,  terraces  are  found  along  Mazon  River  and  its 
tributaries,  Claypool  Ditch  and  Johnny  Run.  Along  the  Mazon  these  are 
especially  well  developed  below  Tieders  Ford  in  section  36  of  Wauponsee 
Township  (T.  33  N.,  R.  7  E.).  Farther  west  the  same  relations  hold  on 
the  downstream  portion  of  both  Waupecan  Creek  and  Bills  Run. 


PLEISTOCENE    SYSTEM 


71 


As  is  pointed  out  in  another  connection,  the  trend  of  the  streams  them- 
selves is  evidence  of  the  sort  of  adjustment  to  new  levels  by  which  these 
terraces  have  been  developed. 

Recent  Deposits 

The  deposits  of  Recent  age  comprise  alluvium  of  present  streams  and 
dune  sands.     The  area  of  the  former  amounts  to  12  or  15  square  miles  in 


Fig.   38.      Close-up  of  gravels  shown   in   fig.   37.     The  distinction 

between  the  till  and  the  overlying  gravels  is  clear,  while 

the  stratification  of  the  latter  is  less  apparent 

than  in  the  preceding  view 

the  floodplains  of  the  Illinois  and  its  tributaries.  This  is  mainly  a  black, 
more  or  less  sandy  silt  having  a  relatively  high  content  of  organic  matter. 
It  provides  excellent  soil  and  where  drained  properly  produces  good  crops. 
It  is  restricted  approximately  to  the  area  lying  below  the  500-foot  level  along 
the   Illinois,  but  appears   at  somewhat   greater  elevation  along  the   smaller 


72  GEOl.OGV    OF    MORRIS    QUADRANGLE 

tributaries.  The  dune  sands  have  already  been  mentioned.  The  more  promi- 
nent areas  are  at  Sand  Ridge  in  Aux  Sable  Township  (T.  34  N.,  R.  8  E.) 
north  of  Illinois  River,  and  at  Sand  Ridge  south  of  Goose  Lake.  The 
former  is  less  than  one  square  mile  in  extent  while  the  latter  covers  more 
or  less  of  five  sections  across  the  north  end  of  Felix  Township  (T.  33  N., 
R.  8  E. )  and  extends  nearly  a  mile  farther  into  Will  County. 

Southeast  of  Coal  City  the  sandy  character  of  the  surface  is  noticeable, 
although  there  has  been  but  little  dune  formation.  East  of  the  county  line, 
however,  the  development  of  dunes  is  so  marked  as  to  dominate  the  topog- 
raphy and  to  indicate  the  origin  of  the  sandy  covering  of  the  surface  at  all 
levels  in  the  southeast  part  of  the  Morris  quadrangle. 

Mention  has  already  been  made  of  the  limited  dune  development  south- 
west of  Devine  Station  in  section  5  of  Goose  Lake  Township  (T.  33  N., 
R.  8  E.).  Here  the  advancing  sand  has  so  nearly  buried  the  original  fence 
posts  that  a  second  fence  has  been  constructed  above  the  first. 

Average  samples  of  the  sands  from  these  several  dune  areas  were  col- 
lected and  subjected  to  a  simple  mechanical  analysis.  The  chief  points 
observed  were,  ( 1)  the  fineness,  angularity,  and  uniformity  of  size  and  com- 
position in  the  sand  from  southeast  of  Coal  City;  (2)  the  relative  coarseness 
of  the  sand  from  the  southern  Sand  Ridge,  and  its  content  of  stony  matter; 
(3)  the  dark  color  and  wide  range  in  size  and  composition  of  the  sand  near 
Devine ;  and  (4)  the  well-rounded  shapes  and  content  of  calcite  in  the  sand 
from  Sand  Ridge  north  of  Illinois  River. 

While  detailed  analysis  of  these  data  is  out  of  place  here,  the  general 
conclusions  are  of  interest.  { 1 )  It  is  clear  from  the  differences  in  shape  and 
composition  that  these  sands  did  not  have  a  common  source  just  prior  to 
their  latest  deposition.  This,  together  with  the  fact  that  the  dunes  lie  at 
several  levels  indicates  a  difiference  in  age.  Although  conceivably  the  dunes 
were  contemporaneous,  the  inference  of  a  difference  in  age  is  borne  out  by 
the  fact  that  the  most  active  dunes  are  at  the  edge  of  the  present  floodplain 
while  those  at  the  540-  and  560-foot  levels  have  been  subdued  in  large  part 
by  advancing  vegetation.  (2)  Sand  from  southeast  of  Coal  City,  although 
angular,  probably  has  been  carried  by  water  as  indicated  by  the  uniformity 
in  size  of  the  grains.  These  are  probably  of  smaller  size  than  would  be 
rounded  in  the  course  of  stream  transportation.  This  favors  the  assumption 
that  these  sands  were  blown  from  a  delta  formed  by  the  Kankakee  where 
it  entered  Lake  Morris.  The  wide  expanse  of  the  sand  southwest  of  Wil- 
mington made  possible  the  development  of  extensive  dunes  without  the  intro- 
duction of  much  foreign  material.  (3)  The  sand  from  the  contact  of  the 
floodplain  of  Illinois  River  with  the  older  gravel  flat  contains  a  considerable 
amount  of  alluvium  with  organic  matter  which  does  not  appear  in  the  other 
sands.     The  burden  of  silt  with  much  organic  matter  now  carried  bv  Illinois 


PLEISTOCENE    SYSTEM  12> 

River  is  obviously  of  recent  origin  and  must  have  been  acquired  in  post- 
glacial time.  The  presence  of  considerable  amounts  of  this  silt  in  the  border- 
ing dunes  bears  out  the  inference  that  these  are  of  late  origin. 

The  sand  deposits  presumably  are  not  thick.  The  maxinuim  thickness, 
as  determined  by  observing  the  relative  elevation  of  the  tops  of  the  dunes 
and  that  of  adjacent  flats,  is  about  20  feet,  but  the  average  is  much  less,  prob- 
ably less  than  five  feet.  If  there  be  included  in  the  dune  area  that  portion 
surrounding  the  actual  dunes  on  which  surface  sand  is  prominent,  the  area 
involved  would  be  several  times  greater  and  the  average  thickness  a  matter 
of  a  few  inches. 


CHAPTER  IV— STRUCTURAL  GEOLOGY 

The  attitude  of  the  rocks  of  the  Morris  quadrangle  was  discussed  in  part 
in  the  chapter  on  descriptive  geology,  but  in  order  to  bring  out  the  general 
structural  relation  the  facts  are  reviewed. 

The  Morris  region  is  one  of  nearly  flat-lying  rocks  with  few  horizon 
markers.  The  few  outcrops  and  relative  scarcity  of  well  data,  in  combina- 
tion with  the  feature  just  noted,  make  accurate  determination  of  structure 
difficult  and  detailed  determination  impracticable,  except  locally. 

The  St.  Peter  sandstone  was  reached  in  more  than  50  wells  plotted  on 
Plate  IL  Contours  drawn  on  Plate  III  to  show  the  configuration  of  the 
surface  of  the  formation  indicate  a  rather  uniform  dip  to  the  southeast.  That 
this  uniformity  is  apparent  rather  than  real  is  suggested  by  the  departure 
therefrom  where  more  numerous  well  logs  are  available,  but  the  general 
southeast  dip  of  about  28  feet  per  mile  is  demonstrated,  the  altitude  of  the 
upper  surface  of  the  sandstone  ranging  from  544  feet  above  sea  level  at  the 
northwest  to  75  feet  below  sea  level  at  the  southeast. 

Comparison  of  elevations  on  the  upper  surface  of  the  Galena-Platteville 
formation  fails  to  reveal  the  structure  because  of  the  truncation  of  the  beds 
by  erosion.  Consequently  no  difference  between  the  altitude  of  the  St.  Peter 
sandstone  and  that  of  the  overlying  formation  can  be  determined.  Whether 
these  beds  conform  to  the  Morris-Kankakee  anticline  noted  by  Cady"^  is 
therefore  not  known.  This  postulated  deformation,  however,  is  merely  a 
broad  low  arching  of  the  beds,  and  may  prove  to  be  non-existent  when  more 
complete  data  are  at  hand. 

The  areal  distribution  of  the  Maquoketa  formation  in  the  north  half  of 
the  quadrangle  indicates  a  low  east  dip  which  does  not  exceed  and  may  con- 
form to  the  dip  of  the  St.  Peter  sandstone.  Well  records  do  not  clearly  indi- 
cate the  Maquoketa  area  in  the  south  half  and  hence  the  structure  cannot  be 
ascertained. 

If  the  Maquoketa  is  present  in  the  southeastern  part  of  the  quadrangle, 
as  suggested  by  the  interpretation  of  logs  riuoted  earlier  (p.  34).  the  forma- 
tion may  be  assumed  to  be  conformable  to  the  postulated  Morris-Kankakee 
anticline. 

The  structure  of  the  Pennsylvanian  beds  as  a  whole  seems  to  be  inde- 
pendent of  the  low  arching  just  noted.  On  the  basis  of  the  structure  of 
No.  2  coal,  the  base  of  the  Carbondale  formation,  the  Pennsylvanian  beds 
dip  southwest  at  a  low  angle  and  this  general  attitude  is  interrupted  by  a 


-'Cady,  G.  H.,  The  Structure  of  the  La  Salle  anticline:    111.  State  Geol.  Survey  Bull.  36.  p.  IM.  1920. 

75 


76  GEOLOGY    OF    MORRIS    QUADRANGLE 

southwest-pitching  syncline  or  basin  with  very  low  slopes  west  of  Coal  Citj-, 
and  a  parallel  broad  down-warp  in  the  vicinity  of  Bills  Run. 

It  thus  becomes  evident  that  the  rocks  of  this  region  have  suffered  more 
than  one  deformative  movement.  The  first  here  recorded  occurred  in  the 
interval  between  the  deposition  of  the  St.  Peter  and  the  Pottsville  beds. 
This  may  have  been  merely  a  tilting  of  the  surface  toward  the  southeast. 

The  folding  along  the  Morris-Kankakee  anticline,  if  any  occurred,  may 
have  taken  place  in  pre-Pennsylvanian  time  since  the  later  beds  do  not  appear 
to  be  involved. 

A  still  later  movement  followed  the  deposition  of  the  Pennsylvanian 
beds  of  this  area.  This  resulted  in  the  general  southeast  dip  shown  by  this 
series.  The  cross-warping  which  developed  the  shallow  synclinal  troughs 
of  Morris   (No.  2)  coal  may  have  occurred  at  the  same  time  or  later. 

It  is  evident  from  their  areal  pattern  as  well  as  their  proximity  to  the 
line  of  maximum  deformation,  that  all  the  rocks  of  this  quadrangle  were 
involved  in  the  series  of  movements  resulting  in  the  La  Salle  anticline.  It  is 
possible,  however,  that  the  postulated  Coal  City  arch  has  been  of  equal  impor- 
tance in  determining  local  structures.  The  time  and  structural  relations  of 
these  two  units  is  beyond  the  scope  of  this  report,  and  it  suffices  to  point 
out  that  the  movements  in  this  area  conceivably  were  contemporaneous  with 
those  listed  by  Cady  for  the  development  of  the  La  Salle  fold."* 

Although  the  Eastern  Interior  Coal  Basin  is  a  stratigraphic  or  physio- 
graphic rather  than  structural  feature,  it  is  well  to  note  its  relation  to  the 
Morris  beds.  As  has  been  pointed  out,  the  general  coal  basin  of  which  this 
area  is  a  part  comprises  most  of  the  State  of  Illinois  as  well  as  parts  of  the 
states  adjoining  on  the  east,  south,  and  west.  The  deeper  portion  of  the 
basin  lies  in  the  southern  part  of  Illinois.  The  old  surface  of  deposition 
slopes  toward  this  deeper  part  from  all  sides.  In  the  Morris  area  this  slope 
probably  was  of  different  angles  at  various  times,  through  deformative  move- 
ments, but  was  probably  at  no  time  far  from  flat.  The  uniform  thickness 
and  character  of  No.  2  coal  for  example,  indicates  essentially  uniform  condi- 
tions for  deposition  over  the  entire  area  where  that  bed  now  exists.  It  is 
clear,  also,  that  the  original  margin  of  the  depositional  basin  was  north  of 
the  present  edge  of  Pennsylvanian  beds.  It  is  not  apparent,  therefore,  that 
the  present  attitude  of  the  Pennsylvanian  strata  is  due  in  any  degree  to  the 
proximity  of  the  area  under  investigation  to  the  margin  of  the  basin  of 
deposition. 

Minor  folding  of  the  pre-Pennsylvanian  beds  has  been  noted  in  the 
description  of  those  strata.  Except  where  revealed  by  the  limited  outcrops 
the  details  of  these  minor  and  more  or  less  localized  structures  cannot  be 
ascertained.     It  is  obviously  probable,  however,  that  such  structures  do  occur 

"Cady,  G.  H.,  Structure  of  the  La  Salle  anticline:    111.  State  Geol.  Survey  Bull.  36,  p.  17.5,  1920. 


STRUCTURAL   GEOLOGY  11 

and  have  their  effect  in  the  minor  intricacies  of  the  areal  patterns  and  in  the 
disposition  of  the  later  deposits  as  well. 

The  minor  structures  affecting  the  Pennsylvanian  strata  are  of  much 
the  same  order  of  magnitude  as  those  noted  for  the  pre-Pennsylvanian  rocks. 
Because  of  the  more  extensive  outcrops  and  the  development  of  the  coal 
properties,  however,  the  details  are  somewhat  better  known.  These  struc- 
tures include  some  minor  faulting  as  well  as  folding.  In  the  upper  beds  of 
this  system  as  exposed  along  Mazon  River,  the  usually  low  and  distinctly 
local  warping  is  so  common  as  to  constitute  the  rule  rather  than  the  excep- 
tion. Such  deviation  from  a  fiat-lying  position  as  that  in  the  center  of  sec- 
tion 25  of  Wauponsee  Township  (T.  ZZ  N.,  R.  7  E.)  is  typical.  Another 
example  may  be  seen  just  below  the  sharp  bend  in  SE.  ]/x  section  19  of 
Felix  Township  (T.  33  N.,  R.  8  E.),  where  a  monoclinal  flexure  giving  10° 
dips  affects  the  beds  for  a  few  yards.  Similar  structures  are  commonly  met 
in  coal-mining  operations  in  this  region.  Cady''^  has  introduced  rather 
detailed  descriptions  of  some  of  these  structures,  of  which  the  most  impor- 
tant is  probably  that  encountered  in  the  Coal  City  area  where  No.  2  coal 
occupies  a  trough  about  1,000  feet  wide  and  50  feet  deep,  trending  north- 
south. 

Faulting  does  not  appear  to  be  commonly  of  more  than  a  foot  or  two 
displacement,  and  no  extensive  faults  have  been  discovered.  Such  move- 
ments of  this  type  as  have  occurred  are  probably  referable  to  local  differences 
in  contraction  and  compression  of  sediments  during  solidification  rather  than 
to  regional  stresses.  Small  dislocations  are  frequently  noted  underground, 
and  on  the  surface  where  the  rocks  have  an  essentially  vertical  exposure  they 
commonly  show  similar  fractures.  Such  a  one  appears  just  below  the  bridge 
at  Pine  Bluff.  Here  the  vertical  component  of  the  movement  is  measured 
in  inches. 


23Cady,  G.  H.,  Coal  Resources  of  District  I  (Longwall):    HI.  Coal  Mining  Investigations  Bull.  10,  1915 


CHAPTER  V— HISTORICAL  GEOLOGY 

The  foregoing  presentation  of  data  concerning  the  character,  disposi- 
tion, and  stratigraphic  relations  of  the  various  formations  of  the  area  is  the 
basis  for  inferences  regarding  the  depositional  and  erosional  conditions  in 
times  past  which  in  turn  lead  to  certain  conclusions  as  to  the  sequence  of 
events  in  this  region.  The  province  of  this  chapter  is  the  delineation  of  these 
events  so  as  to  bring  out  their  interrelations. 

Of  the  time  earlier  than  the  Paleozoic  there  is  no  available  record.  The 
geographic  position  of  the  Morris  quadrangle  makes  it  probable  that  in  pre- 
Cambrian  time  this  region  was  subjected  to  erosion  which  reduced  the  land 
to  an  essentially  plane  surface.  No  drilling  records  are  at  hand  showing  the 
character  of  the  material  composing  this  surface,  but  by  comparison  with 
the  area  in  Wisconsin,  where  this  old  surface  is  exposed,  it  becomes  clear 
that  below  the  sediments  of  Cambrian  age  lies  an  unknown  thickness  of  crys- 
talline rocks,  probably  in  part  igneous  but  largely  metamorphic.  These  con- 
stitute a  lithologically  complex  foundation  for  all  later  sediments.  At  the 
opening  of  the  Cambrian  period,  then,  this  region  was  perhaps  a  low-lying 
land  mass,  with  little  relief  or  roughness. 

The  Cambrian  Period 

During  the  first  part  of  the  Cambrian  period,  with  which  the  Paleozoic 
era  began,  the  condition  of  the  preceding  period  probably  obtained,  since  there 
is  no  evidence  in  the  surrounding  area  indicative  of  an  early  encroachment 
by  the  sea.  Later  in  the  Cambrian,  however,  the  relative  sinking  of  the  land 
brought  it  beneath  the  sea  which  encroached  from  the  south,  and  there  was 
deposited  a  considerable  thickness  of  sandstones  and  some  shales  and  lime- 
stones collectively  known  to  drillers  as  the  "Potsdam  sandstone"  and  here 
designated  "Croixan."  Seven  hundred  feet  of  deposits  of  this  period  are 
reported  in  the  Hoge  log  which  was  given  in  full  in  an  earlier  chapter 
(p.  15).  Records  elsewhere  show  a  maximum  of  about  1,000  feet  deposited 
in  this  period. 

The  Ordovician  Period 

At  the  close  of  the  Cambrian  period,  as  appears  from  evidence  reported 
from  outside  the  quadrangle,  the  area  had  emerged  from  the  sea,  and  under- 
gone extensive  erosion.  But  early  in  the  Ordovician  period  readvance  of  the 
sea  made  possible  further  deposition,  and  the  very  considerable  thickness  of 
sandstones,  limestones,  and  shale  followed  with  relatively  slight  interruption. 
It  is  clear  from  the  varied  character  of  these  beds  that  the  conditions  obtain- 

79 


80  GEOLOGY    OF    MORRIS    QUADRANGLE 

ing  were  not  as  uniform  during  the  Ordovician  period  as  during  the  Cam- 
brian. The  Oneota  dolomite  was  followed  by  the  New  Richmond  sand- 
stone. A  return  to  earlier  conditions  preceded  the  deposition  of  the  Shakopee 
dolomite.  From  the  larger  amount  of  clastic  material  of  Shakopee  age  east 
and  north  of  this  quadrangle  it  may  be  inferred  that  the  land  mass  which 
furnished  the  sediments  lay  in  that  direction  with  the  open  sea  to  the  south 
and  west. 

Evidence  from  nearby  areas  indicates  that  there  was  a  return  to  land 
conditions  for  a  time  after  the  deposition  of  the  Shakopee  dolomite.  This 
resulted  in  the  development  of  an  uneven  erosion  surface  upon  which,  during 
the  succeeding  submergence,  the  St.  Peter  sandstone  was  deposited.  The 
details  of  the  conditions  obtaining  are  not  determined  from  data  gathered  in 
the  IVIorris  quadrangle,  yet  it  is  evident  that  the  deposition  of  this  wide- 
spread blanket  of  nearly  snow-white  sand  could  only  take  place  under  unusual 
conditions.  These  have  been  postulated  variously  by  different  authors,  but 
it  seems  probable  that  the  St.  Peter  sandstone  is  mainly  water-laid  rather 
than  eolian  sediment  although  laid  down  so  near  shore  as  to  have  received 
much  wind-borne  sand. 

A  period  of  erosion  following  the  deposition  of  the  St.  Peter  sandstone 
is  suggested  by  the  apparent  irregularity  of  the  upper  surface  of  the  forma- 
tion. This  is  in  harmony  with  the  unconformity  at  the  top  of  this  forma- 
tion at  its  outcrops  in  La  Salle  County.  At  some  time  after  the  deposition  of 
the  St.  Peter  sandstone  there  appears  to  have  been  a  slight  deformative 
movement  which  resulted  in  a  tilting  of  the  surface  toward  the  southeast. 
The  deep  burial  of  the  beds  prevents  demonstration  of  this  movement.  The 
later  transgression  by  the  sea  brought  about  conditions  favorable  for  further 
deposition,  and  on  top  of  this  uneven  surface  of  St.  Peter  sandstone  was  laid 
the  Platteville  limestone.  With  but  an  inconspicuous  break  in  deposition,  if 
any  occurred,  the  Galena  formation  followed,  a  massive  dolomite  several  hun- 
dred feet  thick. 

Following  the  deposition  of  the  Galena  dolomite  a  change  in  conditions 
permitted  a  thinner  series  of  muds  to  be  laid  down.  These  were  in  part 
calcareous,  and  hardened  into  the  shale  member  of  the  Maquoketa  formation. 
This  change  may  have  involved  a  recession  of  the  sea  or  may  have  been 
occasioned  by  shifting  in  land  drainage.  The  apparently  clean-cut  break 
from  the  dolomii:e  to  the  shale  is  in  harmony  with  a  land  emergence,  which 
may  have  been  slight  and  brief.  IMud  deposition  continued  until  enough  to 
produce  some  60  or  70  feet  of  shale  had  been  laid  down,  and  then  the  intro- 
duction of  calcareous  material  began.  This  resulted  in  a  series  of  shales 
with  the  interbedded  lenses  of  impure  limestone,  followed  by  some  50  feet 
of  limestone.  The  purity  of  this  upper  calcareous  deposit  indicates  clear 
water  conditions  in  contrast  with  the  muddy  waters  of  early  IMaquoketa  time. 


HISTORICAL    GEOLOGY  81 

The  proximity  of  this  area  to  the  shore  Hne  of  the  Mafjuoketa  sea  is 
suggested  both  by  the  change  in  depositional  conditions  and  by  the  variation 
in  shale  and  Hme  proportions  shown  by  logs  from  this  and  adjoining  areas. 
The  greater  thickness  of  limestones  and  shales  to  the  east  in  Will  County 
suggests  that  the  sea  came  in  from  that  direction.  There  is  nothing  to  indi- 
cate, however,  that  the  shore  line  was  within  the  Morris  (juadrangle. 

The  record  of  deformation  during  the  later  Ordovician  is  scanty.  It 
seems  plausible  that  the  several  changes  in  position  of  the  shore  line  were 
accompanied  by  more  or  less  uneven  uplift  or  depression  of  the  area  involved. 

The  postulated  uplift  along  the  Coal  City  axis,  involving  all  pre-Penn- 
sylvanian  beds,  is  the  only  other  important  event  suggested  by  the  evidence 
at  hand. 

The  absence  of  any  sediments  belonging  to  the  periods  between  the 
Ordovician  and  the  Pennsylvanian,  leaves  the  history  of  this  interval  some- 
what in  doubt,  yet  suggestive  relations  of  rocks  to  the  east  may  be  noted  in 
this  connection. 

East  of  the  Morris  quadrangle  the  Maquoketa  formation  is  overlain 
unconformably  by  Silurian  beds  of  either  Alexandrian  or  Niagaran  age.  It 
is  apparent  that  the  Alexandrian  sea  may  have  covered  part  or  all  of  the 
Morris  area,  and  its  deposit  later  been  eroded.  While  no  trace  of  Niagaran 
beds  appears  in  the  Morris  region,  their  presence  west  of  the  La  Salle  fold 
as  well  as  in  the  eastern  part  of  the  State  makes  plausible  the  assumption  of 
transgression  by  the  sea  at  that  time.  Except  for  the  complete  absence  of 
all  deposits  later  than  Maquoketa  there  is  no  record  of  events  of  post- 
Ordovician  and  pre-Pennsylvanian  time.  We  know  only  that  erosion  pre- 
vailed. From  evidence  in  other  parts  of  northern  Illinois,  it  seems  probable 
that  the  sea  covered  the  Morris  region  at  least  twice  during  the  Silurian  and 
Devonian  periods. 

The  Pennsylvanian  Period 

With  the  opening  of  this  period  began  the  last  widespread  deposition  by 
water  in  the  part  of  Illinois  which  includes  the  area  under  investigation. 
Because  of  the  character  of  the  deposits  made  during  this  period  it  is  the 
most  important  from  an  economic  standpoint.  During  early  Pottsville  time, 
while  deposits  were  being  made  in  the  deeper  parts  of  the  Eastern  Interior 
Basin,  the  Morris  region  continued  to  be  subject  to  the  processes  of  weather- 
ing and  erosion.  Somewhat  later,  however,  the  northward  extension  of  the 
area  of  deposition  resulted  in  the  formation  of  a  series  of  sandstones,  shales, 
clays,  and  thin  coals.  These  reveal  shallow  water  and  shore  conditions  with 
subordinate  marshes  supporting  abundant  vegetation.  These  latter  were  of 
limited  areal  extent  and  short  lived  so  that  no  notable  accumulation  of  peaty 
matter  resulted. 


82  GEOLOGY    OF    MORRIS    QUADRANGLE 

At  the  time  of  the  deposition  of  No.  2  coal,  a  more  widespread  uniform- 
ity of  conditions  was  inaugurated.  No.  2  coal  itself,  while  showing  some 
variation  in  thickness,  is  essentially  uniform  throughout  not  only  the  Morris 
quadrangle,  but  throughout  an  area  which  possibly  includes  much  of  the 
Illinois  coal  field.  A  distinct  change  in  conditions  is  thus  demonstrated,  for 
the  extent  of  any  of  the  Pottsville  sediments  is  markedly  restricted.  The 
marsh  conditions,  under  which  No.  2  coal  was  deposited,  were  followed  by 
conditions  permitting  the  introduction  of  mud  and  sand.  In  these  sediments 
the  cross  bedding,  lenticular  character,  and  horizontal  as  well  as  vertical 
variation  in  composition  suggests  constantly  changing  conditions.  This  fea- 
ture, considered  in  connection  with  the  aggregation  of  argillaceous  and  arena- 
ceous material  of  varied  types  implies  a  continental  rather  than  marine  area 
of  deposition. 

That  the  deposition  did  not  continue  uninterruptedly  is  shown  by  the 
marked  breaks  amounting  to  local  unconformities  noted  in  another  connec- 
tion. How  widespread  these  were  cannot  be  determined  from  present  data, 
which,  however,  do  indicate  that  considerable  portions  of  the  quadrangle  at 
least  were  involved.  The  differences  in  contemporaneous  sediments  in  dif- 
ferent parts  of  the  area  are  indicated  by  the  apparent  restriction  of  the  well- 
known  Mazon  fossil  beds  to  a  small  area.  While  more  complete  data  may 
show  a  widespread  stratum  of  this  type,  the  two  "fossil  beds"  exposed  were 
apparently  deposited  in  a  limited  basin.  The  lateral  gradation  from  argilla- 
ceous to  distinctly  arenaceous  types  of  material  appears  clear,  and  indicates 
a  more  or  less  secluded  or  sheltered  area  of  deposition  of  the  fine  muds  com- 
prising the  fossiliferous  shales.  The  fossil  content  of  the  latter  proves  their 
non-marine  origin. 

For  a  considerable  period  after  the  deposition  of  No.  2  coal,  land 
conditions  obtained  as  shown  by  the  irregular  alternations  of  sandstone,  shaly 
sandstone,  sandy  shale,  and  calcareous  clastic  beds  with  thin  and  locally 
developed  beds  of  carbonaceous  material.  In  places  the  last  named  are  true 
coals,  but  in  few  places  are  they  thick  enough  to  attract  local  prospectors. 

Toward  the  close  of  the  Carbondale  epoch,  coal-forming  conditions 
existed  somewhat  generally,  and  a  thin  bed,  possibly  to  be  correlated  as  No.  5 
coal,  was  laid  down  over  at  least  the  southwestern  quarter  of  the  quadrangle. 
To  what  extent  this  bed  originally  covered  the  rest  of  the  quadrangle  is  not 
known,  but  well  records  indicate  that  subsequent  erosion  removed  all  trace 
of  such  beds,  if  they  were  ever  present,  over  most  of  Felix  and  Goose  Lake 
townships.  The  data  are  insufficient  to  warrant  inference  on  this  point  from 
generalizations  as  to  thickness  or  relation  to  No.  2  coal. 

Whether  deposition  ceased  before  the  close  of  Carbondale  time,  or 
extended  into  the  AIcLeansboro  can  be  determined  only  upon  the  identifica- 
tion of  sediments  of  the  latter  aere.     Present  data  show  an  absence  of  either 


HISTORICAL   GEOLOGY  83 

the  limestone  marking  the  basal  portion  of  the  McLeansboro  beds,  or  of  coals 
which  can  certainly  be  identified  as  No.  6  or  No.  7.  The  facts  at  hand  can 
be  harmonized  easily  with  the  conception  of  a  cessation  of  sedimentation  soon 
after  the  deposition  of  No.  5  coal — the  thin  upper  bed  of  the  Morris  area 
being  provisionally  so  classed — and  the  subjection  of  the  entire  area  to 
weathering  and  erosion  during  the  remaining  pre-glacial  time. 

The  jMesozoic  and  Cenozoic  Eras 

Events  of  Mesozoic  and  Cenozoic  eras  apparently  did  not  involve  deposi- 
tion here  except  during  Quaternary  time.  The  drift  covering  of  the  area 
is  thick,  and  the  scattered  well  records  do  not  reveal  the  pre-glacial  topog- 
raphy in  sufficient  detail  to  make  delineation  of  erosional  changes  possible. 
It  is  nevertheless  clear  that  just  prior  to  the  advent  of  the  ice  the  relief  of 
the  surface  was  moderate,  with  the  possible  exception  of  the  area  adjoining 
the  present  Illinois  \'alley.  (See  fig.  33.)  Here  the  greater  relief  of  the 
bed  rock  surface  may  have  resulted  from  erosion  in  Pleistocene  time,  and 
hence  not  indicate  extensive  pre-glacial  trenching.  From  the  apparent 
development  of  short  tributary  valleys  cut  in  bed  rock,  it  may  be  inferred 
that  a  late  Tertiary  uplift  had  rejuvenated  the  streams  working  over  an  area 
peneplaned  in  post-Paleozoic  time. 

THE  PLEISTOCENE  PERIOD 

The  early  events  of  the  Pleistocene  period  have  been  worked  out  from 
data  gathered  from  many  parts  of  the  North  American  continent.  This  his- 
tory shows  that  during  this  time  there  were  at  least  five  distinct  ice  invasions, 
separated  by  very  long  interglacial  stages.  Beginning  with  the  oldest,  the 
glacial  stages  have  been  called  the  Nebraskan,  the  Kansan,  the  lllinoian,  the 
lowan,  and  the  Wisconsin  (p.  S7).  There  is  no  positive  record  of  the 
Nebraskan  or  of  the  Kansan  invasions  in  this  part  of  Illinois,  although  cer- 
tain deposits  of  old  till  found  in  Bureau  County  have  been  referred  to  a  pre- 
lUinoian  stage  by  Cady,"*  who  also  has  recognized  lllinoian  till  in  the  same 
region.  While  no  deposits  clearly  of  lllinoian  age  have  been  found  in  the 
Morris  quadrangle,  its  geographic  position  with  reference  to  the  area  known 
to  have  been  glaciated  at  that  time  is  such  that  there  is  no  doubt  that  the 
lllinoian  ice-sheet  covered  this  area. 

There  is  no  evidence  indicating  that  ice  covered  the  Morris  region  dur- 
ing the  succeeding  lowan  invasion,  but  there  is  abundant  evidence  that  the 
region  was  almost  continually  beneath  the  ice  until  after  the  Marseilles  stage 
of  the  W^isconsin  epoch. 

During  the  Wisconsin  epoch  it  is  believed  that  the  ice  front  oscillated 
repeatedly,  but  that  at  times  it  was  essentially   stationary  long  enough   to 

-'Cady,  G.  H.,  Geologv  and  mineral  resources  of  the  Hennepin  and  La  Salle  quadrani;les:    III.  State  Geol 
Survey  Bull.  37,  p.  70,  1919. 


84  GEOLOGY    OF    MORRIS    QUADRANGLE 

permit  the  accumulation  of  great  belts  of  till  and  associated  deposits  at 
and  under  its  edge.  These  ridges,  or  terminal  moraines,  dominate  the  topog- 
raphy in  many  parts  of  the  State,  and  include  the  ridges  known  as  the 
Shelby ville,  Bloomington,  Marseilles,  Minooka,  Valparaiso  and  Lake  Border 
moraines,  respectively. 

The  history  of  only  the  latter  part  of  the  Pleistocene  period  is  recorded 
within  the  Morris  area.  It  is  clear  that  the  region  was  overwhelmed  by 
continental  ice  sheets  earlier  than  the  local  depositional  record  suggests. 
It  was  probably  covered  by  deposits  of  glacial  origin  during  the  Illinoian 
invasion  as  well  as  during  the  early  advances  of  the  Wisconsin  ice,  but  if  so, 
most  of  the  deposited  material,  and  presumably  some  of  the  bed  rock  as 
well,  was  removed  during  the  succeeding  interglacial  stage  or  the  following 
ice  invasion.  The  presence  of  glacial  striae  on  the  bed  rock  surface  trend- 
ing about  S.  50°  W.  (PI.  Ill)  indicates  erosion  by  ice  in  pre-Marseilles 
time  since  the  trend  of  the  terminal  ridge  of  that  time  indicates  westward- 
moving  ice.  So  few  such  surfaces  are  observable,  however,  that  the  ref- 
erence of  the  striae  to  a  certain  invasion  is  not  feasible. 

The  till  and  associated  deposits  comprising  the  surface  of  this  area 
were  spread  out  during  the  latter  part  of  the  Wisconsin  epoch.  It  is 
probable  that  the  ice  which  formed  the  Bloomington  moraine  and  is  known 
to  have  made  deposits  of  considerable  extent  and  thickness  in  the  area 
west  of  the  Morris  quadrangle  also  left  more  or  less  debris  in  the  latter 
region.  After  the  recession  of  the  ice  of  the  Bloomington  stage,  a  lake 
was  formed  over  the  area  between  Morris  and  Seneca.  In  this  lake  were 
deposited  the  laminated  clays  found  at  various  points  between  these  places 
and  utilized  for  tile  manufacture  at  Morris.  The  altitude  of  the  clays  shows 
that  the  level  of  this  lake  was  above  530  feet.  The  beds  may  be  referable 
to  a  600- foot  lake  postulated  by  Leighton  on  evidence  noted  farther  down 
the  valley,  but  the  identity  of  these  two  lakes  is  not  demonstrated."^  The 
areal  extent  of  this  lake  is  problematical.  To  the  west,  no  limit  can  be  set 
from  data  gathered  within  this  quadrangle.  To  the  east,  the  Morris  basin 
must  have  been  inundated  as  far  as  the  recession  of  the  Bloomington  ice 
permitted  until  a  large  part  of  the  quadrangle  was  under  water.  The  lake 
boundary  at  the  south,  east  or  north  may  have  been  considerably  outside 
the  limits  of  the  Morris  area,''^  while  on  the  west  the  Bloomington  morainic 
ridge  limited  the  spreading  waters. 

THE    MARSEILLES    STAGE 

The  advent  of  the  Marseilles  ice  must  have  eliminated  the  eastern 
portion  of  the  lake  east  of  the  Marseilles  morainic  ridge,  which  apparently 


JsUnpublished  notes. 

56Recent  work  by  Mr.  D.  J.  Fisher,  of  the  Illinois  State  Geological  Survey  has  shown  the  presence  of 
lake  sands  and  larrinatel  clays  referable  to  this  lake  in  the  Des  Plaines  valley. 


HISTORICAL   GEOLOGY  85 

marks  the  western  limit  of  the  next  ice  advance  and  forms  the  west 
boundary  of  the  Morris  Basin.  At  the  time  of  the  formation  of  this 
moraine  the  ice  front  stood  at  the  position  of  this  elevated  area  and  the 
waters  from  the  ice  found  their  way  westward  presumably  down  the  Fox 
and  Illinois  valleys.  During  this  period  Morris  Basin  probably  was  some- 
what aggraded  by  the  ice,  as  there  would  be  little  erosive  action  so  near  the 
ice  front. 

With  the  retreat  of  the  ice  front  to  a  position  slightly  behind  the  crest 
of  the  Marseilles  moraine  there  must  have  been  developed  a  series  of  ponds 
between  the  moraine  and  the  ice.  These  would  fill  until  an  outlet  was 
found,  through  which  the  overflow  would  escape  in  a  series  of  separate 
streams.  With  continued  ice  recession  the  ponds  would  develop  into  pro- 
glacial  lakes  dammed  by  the  moraine  on  the  west  and  the  ice  on  the  east. 

The  early  water  level  of  these  lakes  probably  was  more  than  700  feet 
above  the  sea,  but  it  is  unlikely  that  this  level  was  long  maintained.  Erosion 
at  the  outlets  lowered  the  water  level  and  slightly  reduced  the  area  sub- 
merged. On  the  other  hand  the  recession  of  the  ice  eastward  would  have 
uncovered  relatively  flat  land  and  may  have  greatly  increased  the  area 
flooded.  By  the  time  the  ice  front  had  reached  the  west  side  of  the  Morris 
quadrangle  the  outlet  across  the  morainic  dam  probably  had  been  cut  down 
to  about  600  feet. 

There  is  little  evidence  to  show  that  the  ice  front  did  not  retreat  at  a 
regular  rate  across  the  Morris  Basin.  Had  it  remained  stationary  for  any 
considerable  period  of  time  a  deposit  similar  in  character  to  the  Marseilles 
moraine  would  have  been  formed,  and  its  size  would  have  been  related  to 
the  time  involved.  Such  deposit  is  found  near  the  west  limit  of  the 
quadrangle,  where  a  line  of  low  ridges,  locally  little  more  than  knolls, 
trends  northeastward  across  the  middle  of  Nettle  Creek  Township  (T.  34  N., 
R.  6E.),  continuing  as  far  as  Central. 

There  is  no  evidence  to  indicate  that  after  this  halt  the  ice  did  not 
gradually  retreat  to  the  east,  at  least  as  far  as  the  vicinity  of  Minooka 
ridge. 

While  the  events  previously  noted  were  taking  place,  similar  conditions 
obtained  south  of  the  river.  The  lesser  height  of  the  main  morainic  ridge 
to  the  west  precluded  the  presence  of  any  ponds  above  the  700-foot  level, 
and  indeed  the  area  in  which  a  lake  of  even  that  level  could  have  been  main- 
tained is  small.  Below  that  level,  as  at  680  and  660  feet,  there  are  wide 
flats,  but  the  absence  of  higher  limiting  areas  makes  problematical  the  pres- 
ence of  any  lakes  in  this  region  comparable  in  size  or  level  with  those  to 
the  north. 

It  is  probable  that  during  its  recession  the  ice  front  would  show  pro- 
gressively   a    more    regular    outline    in    its    larger    features    while    possibly 


86  GEOLOGY   OF    MORRIS   QUADRANGLE 

minor  irregularities  would  be  increased.  Thus  the  projection  of  the  ice 
occupying  the  site  of  the  present  Illinois  valley  would  be  eliminated  grad- 
ually, the  front  developing  a  rounded  outline  only  roughly  parallel  to  the 
Marseilles  moraine.  By  the  time  the  ice  had  retreated  as  far  as  Seneca 
it  is  probable  that  the  waters  from  north  and  south  were  uniting  to  form 
the  early  Illinois  River.  At  this  time  the  level  of  the  outlet  may  have  been 
held  by  the  morainic  dam  above  600  feet,  perhaps  as  high  as  640,  and  in 
that  case  a  wide  river,  shallow  and  of  low  gradient  may  be  postulated. 
This  water  may  have  been  a  lake  rather  than  a  river,  but  a  long  sinuous 
shape  seems  necessarily  to  have  resulted  from  the  topography  of  the  area. 
The  precise  boundary  of  this  body  of  water  is  not  here  defined. 

\Mth  the  further  retreat  of  the  ice  there  was  exposed  a  much  larger 
area  which  would  have  been  covered  by  the  640- foot  water.  Whether  it 
was  covered  or  not  depended  largely  upon  the  relation  between  the  rate 
of  retreat  of  the  ice  front  and  that  of  the  downcutting  at  the  outlet.  After 
the  union  of  waters  north  and  south  of  the  river,  the  erosion  of  the  single 
valley  across  the  moraine  must  have  proceeded  with  relative  rapidity.  No 
evidence  has  been  found  indicative  of  the  area  covered  by  the  640-foot 
water,  nor  indeed  at  any  level  above  600  feet.  Hence  present  data  lead  to 
the  conclusion  that  the  outlet  across  the  Marseilles  moraine,  if  at  any  time 
higher  than  the  pre-Marseilles  level,  600  feet,  was  reduced  to  that  level 
shortly  after  the  withdrawal  of  the  ice  of  the  Marseilles  stage. 

That  a  body  of  water  existed  at  the  latter  level,  in  post-Marseilles  time, 
is  indicated  by  the  presence  of  a  gravel  and  sand  deposit  in  the  southeast 
quarter  of  section  8,  Erienna  Township  (T.  33  N.,  R.  7  E.),  south  of  Long 
Point  school  (PI.  IIL^i).  A  similar  deposit  was  observed  by  Leighton  about 
a  mile  to  the  northwest.  These  consist  of  well-assorted  gravels  and  sands 
exhibiting  delta  bedding.  The  upper  surfaces  lie  between  600  and  620 
feet  above  sea  level  and  may  be  interpreted  as  deposits  made  at  the  mouths 
of  streams  entering  a  lake  at  that  level. 

The  fact  that  a  lake  at  approximately  this  level  was  in  existence  prior 
to  the  advent  of  the  Marseilles  ice,  as  noted  above  (p.  84),  leads  to  the 
inference  that  after  the  dam  of  morainic  material  at  Marseilles  had  been 
eroded  to  the  600-foot  level,  the  same  obstacle  to  further  erosion  of  this 
valley  which  had  been  operative  in  pre-Marseilles  time,  again  became  the 
controlling  factor  with  the  result  that  a  lake  was  again  maintained  at  that 
level. 

The  duration  of  this  lake  through  any  considerable  period  would  have 
resulted  in  the  production  of  the  usual  depositional  and  erosional  shore 
features  of  such  bodies  of  water.  The  absence  of  these  features  is  good 
negative  evidence  of  the  relatively  early  lowering  of  the  lake  level.  How- 
ever, the  drainage  pattern  of  Nettle  Creek  suggests  that  the  upstream  part 


87 

nt   of 

This 

aving 

iption 

after 
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inage, 

early 

later 
s  has 
lently 

For 
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time 

south 
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•idges 
J  that 
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s  oc- 
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^niWOtiei  i'li«iiiCi,aii*Ol-» 


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ILLINOIS  STATE  GEOLOGICAL  SURVEY 

R.BE. 


BULL.  No.  43,  PLATE  111.1 
n.ioc. 


<V<\\N  Valparaiao  Moraine 

1  J  Minooka  Ridse 

Y/y2j\  Marseilles  -Moraine 

..',■■  '      ^  Lake  Morris  boundary 

,01011.  Crvder  Lake  boundary 


Map  of  Morris  Basin  showing  major  physiographic  features 


JS 


HISTORICAL   GEOLOGY  87 

antedates  the  downstream  part.  There  is  a  much  better  development  of 
tributary  valleys  and  ravines  above  than  below  the  600-foot  level."'  This 
is  the  normal  relation  if  the  mouth  of  the  stream  was  lowered  after  having 
been  at  the  600-foot  level  for  some  time,  and  substantiates  the  assumption 
of  a  600- foot  lake. 

There  is  nothing  in  the  topography  of  the  region  to  indicate  that  after 
the  lowering  of  this  600-foot  lake  there  was  not  a  regular  withdrawal  of 
the  ice  to  the  east,  and  a  nearly  equally  regular  lowering  of  the  level  of  the 
water  by  erosion  of  the  outlet  channel. 

The  shape  of  the  ice-front  during  the  recession  of  the  ice  sheet  was 
at  all  times  an  important  factor  in  the  disposition  of  the  lines  of  drainage, 
ponds  and  associated  deposits.  The  position  of  the  ice  during  the  early 
stages  of  its  retreat  can  be  read  from  the  topography  today,  but  later 
erosion  of  the  valleys  of  the  Illinois,  Des  Plaines  and  Kankakee  rivers  has 
removed  a  large  part  of  the  glacial  deposits  east  of  Morris,  and  consequently 
the  exact  outline  of  the  ice-front  at  any  given  time  is  problematical.  For 
example,  no  evidence  has  been  secured  which  indicates  the  position  of  the 
ice-front — which  was  probably  the  eastern  limit  of  the  water — at  the  time 
the  600-foot  lake  existed. 

Between  that  stage  and  the  time  of  removal  of  the  ice  from  the  south 
half  of  the  quadrangle,  there  is  no  trace  of  the  succeeding  positions  of 
the  front.  North  of  the  river  there  is  a  suggestion  in  the  elongate  ridges 
along  Aux  Sable  Creek  that  the  ice  was  stationary  for  a  time  along  that 
line.  Sand  and  gravel  appear  in  the  N.  E.  34  of  section  9.  Aux  Sable 
Township  (T.  34  N.,  R.  8  E.),  where  they  lie  on  the  west  slope  of  a  ridge 
and  were  apparently  deposited  at  the  edge  of  the  ice.  Whether  this  oc- 
curred during  the  retreat  of  the  Marseilles  ice  or  at  the  time  of  the  forma- 
tion of  Minooka  Ridge  is  not  determined. 

From  the  valley  of  Aux  Sable  Creek  eastward,  all  trace  of  the  deposits 
of  the  Marseilles  ice  is  obliterated  by  the  younger  Minooka  till.  The  extent 
of  the  retreat  of  the  Marseilles  ice  prior  to  the  formation  of  this  deposit 
is  not  known.  It  seems  probable  that  land  as  far  east  as  Joliet  was  uncov- 
ered, although  the  recession  of  the  ice  east  of  the  head  of  the  Illinois  is 
not  demonstrated. 

THE   MINOOK.\  ST.\GE 

Apparently  the  next  important  event,  following  the  recession  of  the 
Marseilles  ice  across  the  Morris  Piasin,  was  the  formation  of  Minooka 
Ridge,  which,  rising  prominently  above  the  basin,  marks  its  northeastern 
margin.  The  time  elapsing  between  these  two  events  can  be  determined 
in  the  broadest  terms  only.     As  compared  with  the  other  interglacial  stages 

2'The  upstream  portion  is  shown  on  the  map  of  the  Marseilles  Quadrangle. 


88  GEOLOGY    OF    MORRIS    QUADRANGLE 

of  Wisconsin  time,  it  probably  was  of  short  duration.  As  pointing  to  this 
conclusion,  there  is  no  indication  of  the  development  of  an  interglacial  soil. 
Indeed,  the  distinction  between  the  two  tills  is  by  no  means  clear  in  some 
places. 

Throughout  the  Minooka  stage  there  was  maintained  in  the  Morris 
Basin  the  lake  which  was  formed  after  the  recession  of  the  Marseilles  ice. 
When  the  Minooka  ice  began  its  retreat  there  ensued  a  series  of  events  of 
the  same  general  type  as  those  noted  for  the  Marseilles  stage.  At  first, 
waters  flowed  across  Minooka  Ridge  in  sec.  13,  T.  36  N.,  R  8.  E.,  as  noted 
by  Leverett."^  These  waters  must  have  followed  the  Aux  Sable  Valley 
to  the  edge  of  the  lake  occupying  the  Morris  Basin.  To  what  extent  the 
waters  from  the  receding  Minooka  ice  overflowed  to  the  southwest  and 
south  can  not  be  told  from  present  topography  since  all  trace  of  any  such 
drainage,  if  it  existed,  has  been  removed  by  subsequent  erosion.  With  the 
details  of  this  retreat  and  of  the  events  during  the  succeeding  Valparaiso 
stage  of  the  ice  in  the  region  northeast  of  Joliet  the  present  report  is  con- 
cerned only  in  so  far  as  these  events  determined  processes  and  results 
down  the  valley  to  the  west. 

The  Lake  Morris  sub-stage.  At  some  time  after  the  withdrawal  of  the 
Marseilles  ice  and  probably  before  the  formation  of  the  Valparaiso  moraine 
the  level  of  the  lake  in  Morris  Basin  was  lowered  from  600  to  560  feet.  As 
already  stated,  it  seems  probable  that  this  lowering  took  place  soon  after  the 
withdrawal  of  the  IMarseilles  ice.  The  absence  of  outwash  from  the  Minooka 
till  ridge  in  the  nature  of  delta  deposits  referable  to  the  600-foot  stage 
substantiates  this  view.  As  in  the  case  of  the  600-foot  lake,  the  site  of 
the  obstruction  for  the  560-foot  water  lies  west  of  the  Morris  quadrangle. 
It  is  clear  that  the  downcutting  of  the  outlet  would  progress  rapidly  until 
bed  rock  beneath  the  till  was  reached.  The  presence  of  Pennsylvanian  strata 
in  the  valley  walls  near  Marseilles  up  to  about  560  feet"^  may  have  been 
the  cause  of  the  maintenance  of  a  lake  at  that  level  in  the  Morris  Basin. 
Any  extension  of  the  lake  west  of  the  site  of  Morris  must  have  been  little 
more  than  a  widened  river,  since  the  560-foot  contour  lines  converge  sharply 
there. 

Suggestion  that  the  water  level  was  maintained  at  about  560  feet  for 
a  much  longer  time  than  at  any  higher  level  in  the  Morris  Basin  is  found 
in  the  more  abundant  evidence  of  its  existence  at  that  level.  Not  only 
does  the  drainage  pattern  of  Morris  Basin  suggest  such  a  lake  but  there 
are  numerous  deposits  which  by  their  character,  disposition  and  elevation 
practically  fix  the  limits  of  this  body  of  water  (PI.  lllA).  For  convenience 
of  discussion,  this  lake  of  post-Marseilles  age,  which  filled  the  Morris  Basin 

=8Leverett,  Frank,  The  Hlinois  glacial  lobe:    U.  S.  Geol.  Survey  Mon.  38,  p.  319,  1899. 
™Cady,  G.  H.,  Field  notes  on  Ottawa-Marseilles  quadrangles. 


HISTORICAL   GEOLOGY 


up  to  about  the  560-foot  level,  covering  an  area  of  some  150  square  miles, 
is  named  Lake  Morris. 

North  of  the  Illinois  the  evidence  of  this  lake  is  meager.  Isolated, 
inconspicuous  sandy  patches,  such  as  that  transverse  to  Nettle  Creek  in 
section  20  of  Saratoga  Township  (T.  34N.,  R.  7E.),  suggest  a  beach,  but 
the  exact  area  occupied  by  the  water  at  this  level  is  problematical.  There 
is  little  reason  to  believe  that  the  topography  has  been  subsequently  modified 
to  a  greater  degree  here  than  on  the  south,  or  that  the  surface  has  been 
deformed,  and  it  is  assumed  that  the  560-foot  contour  line  marks  the  ap- 
proximate extent  of  the  lake  waters. 

The  Aux  Sable  Valley  must  have  been  in  large  part  covered  by  waters 
of  Lake  Morris.  Although  the  topography  of  the  valley  suggests  some 
aggrading  prior  to  the  recent  erosion  by  the  Aux  Sable,  it  is  not  evident 
that  any  vigorous  erosion  was  taking  place  on  the  west  slope  of  Minooka 
Ridge. 

In  case  the  valley  of  the  Aux  Sable  was  inundated,  the  low  till  ridges 
and  hills  north  of  Sand  Ridge  were  islands.  Their  topography  is  fresh, 
morainic,  and  little  modified  by  stream  action.  Any  shore  features  that  may 
have  been  developed  along  the  southern  margin  of  Minooka  Ridge  have 
been  obliterated  by  subsequent  erosion. 

The  lack  of  a  beach  on  the  north  side  of  the  lake,  contrasted  with  the 
marked  beach  ridge  on  the  southeast,  points  to  certain  controlling  conditions. 
Accumulations  of  beach  material  could  be  derived  only  by  the  reworking 
of  a  large  amount  of  till.  Such  sorting  is  normally  performed  by  rivers 
traversing  the  area  or  by  waves  and  undertow  at  the  beach.  On  the  north, 
only  a  limited  area  was  drained  by  tributaries  to  Lake  Morris,  and  this  region 
was  smooth  and  of  slight  relief.  In  the  short  time  between  the  retreat  of 
the  Marseilles  ice  and  the  lowering  of  the  lake  level  no  systematic  drainage 
developed,  and  hence  the  region  could  not  have  been  subjected  to  vigorous 
stream  action.  Under  these  conditions  little  material  was  brought  to  the 
shore  for  the  building  of  a  beach.  Furthermore,  in  view  of  the  long  gentle 
slope  of  the  lake  bottom,  the  short  life  of  the  lake  itself  precluded  the 
chance  of  enough  shoreward  cutting  to  supply  material  to  make  a  beach 
comparable  with  that  found  elsewhere.  To  the  south  and  east,  however, 
conditions  were  radically  dififerent  and  were  favorable  to  the  development 
of  beaches  of  distinctive  size.  From  the  southeast  along  the  margin  of  the 
ice  came  the  flooded  Kankakee,  overloaded  with  debris  from  the  glacier. 

This  stream  brought  great  quantities  of  fine  gravel,  sand  and  silt  to  the 
lake  and  from  them  the  prominent  beach  could  be  formed.  Under  these  con- 
ditions, a  silt  filling  of  some  consequence  might  be  expected  in  this  region, 
and  evidence  of  such  deposition  is  found  in  auger  borings  on  the  pronounced 
flat  north  of  Coal  City  and  west  of  Wilmington.     Kankakee  River  at  this 


90  GEOLOGY   OF    MORRIS    QUADRANGLE 

time  was  aggrading  its  channel,  and  by  the  close  of  the  stage  of  the  560- foot 
lake,  probably  had  filled  the  valley  in  the  vicinity  of  Ritchey  to  the  560- 
foot  level,  possibly  as  high  as  570  feet,  as  indicated  by  the  gravel  deposits 
remaining  there.  The  valley  here  is  about  two  miles  wide,  so  that  a  consider- 
able filling  is  suggested. 

Downstream,  to  the  north,  the  finer  gravel  and  sand  were  deposited 
in  great  quantity  and  were  spread  over  a  wider  area  by  the  stream,  which, 
on  reaching  the  gentler  slopes  of  the  lake  shore,  was  heavily  overloaded. 
The  absence  of  shore  features  across  the  sand  flat  may  be  ascribed  to 
the  continued  introduction  of  sand  during  and  even  later  than  the  life  of 
the  lake. 

Conditions  on  the  east  side  of  Lake  Morris  were  essentially  the  same 
as  along  the  southeast  shore.  On  both  sides  of  Prairie  Creek,  section  12, 
Wilmington  Township  (T.  33  N.,  R.  9  E.),  Will  County,  are  low  ridges  of 
sand  and  gravel,  suggestive  of  beaches. 

A  similar  deposit  lies  along  Grant  Creek,  north  of  which  a  thick  gravel 
deposit  slightly  above  the  560-foot  level  shows  clearly  the  entrance  to  the 
lake  of  a  heavily  laden  stream  from  the  north.  Northwest  of  this  deposit, 
east  of  Channahon,  similar  deposits  indicate  valley  filling  entirely  across  the 
gap  between  Minooka  Ridge  and  the  similar  till  surface  more  than  four 
miles  to  the  east. 

In  its  early  stages,  the  valley-filling  of  the  Des  Plaines  w^as  in  the  nature 
of  valley-train  deposition,  including  slightly  inclined  beds,  with  current  bed- 
ding prominent.  With  further  retreat  of  the  ice  the  development  of  a  lower 
gradient  resulted. 

That  the  above  noted  heavy  gravel  deposits  of  the  Des  Plaines  \'alley 
are  out  wash  from  the  \'alparaiso  glacier  was  shown  by  Leverett,^°  who 
further  suggested  that  the  abrupt  termination  of  the  gravels  near  Chan- 
nahon was  due  to  the  presence  of  a  lake  in  the  Morris  Basin. 

Just  as  the  history  of  the  Morris  Basin  thus  far  outlined  is  closely  tied 
to  events  in  the  glacial  histon,'  of  the  area  immediately  to  the  northeast,  so 
in  the  later  stages  of  its  history  the  controlling  conditions  are  found  to  be 
in  the  Lake   Michigan   Basin. 

Following  the  \'alparaiso  stage  of  glaciation  came  the  Lake  Border 
stage,  when  the  ice  extended  little  farther  than  the  Lake  :Michigan  de- 
pression. Its  waters,  however,  continued  to  flow  down  the  Des  Plaines  and 
Illinois  valleys. 

The  Crydcr  Lake  sub-stage. — The  downcutting  at  the  outlet  must  have 
continued  during  the  Lake  Morris  sub-stage,  but  when  the  540-foot  level 
was  reached  another  halt  in  the  lowering  of  the  lake  was  made  and  beach 
lines  marking  the  edge  of  the  water  were  formed.     To  this  body  of  water 

3»Leverett.  Frank,  The  Illinois  glacial  lobe:    U.  S.  Geol.  Survey  Mon.  iS.  pp.  377-8,  189Q. 


HISTORICAL    GEOLOOY 


91 


the  name  Crydcr  Lake  is  given,  from  Cryder  school,  which  is  located  on 
the  beach  line,  where  it  is  well  developed  and  preserved.  A  possible  cause 
for  this  halt  in  the  lowering  of  the  lake  is  the  presence  of  a  resistant  sand- 
stone in  the  valley  walls  near  Marseilles  up  to  at  least  the  540-foot  level. 
The  fact  that  this  standstone,  the  W'aupecan,  is  overlain  by  soft  shales  leads 
to  the  inference  that  this  was  a  factor  of  considerable  importance  in  the  rate 
of  downcutting. 

Cryder  Lake  existed  for  some  time  in  the  Morris  Basin,  as  attested 
by  the  good  beach  still  in  evidence.  A  beach  line  at  this  level  may  be  traced 
almost  entirely  around  the  depression  (Tl.  WIA).  It  has  its  best  develop- 
ment north  of  Morris,  where  it  is  in  part  utilized  as  the  site  of  Ridge  Road, 


Fig.   MK      (iravfl  dijiosit  in  src  1\,  Waupnnsee  Twp.      The  larger  r<»  k-<  i.nili.ilih    lia\c   h 
by  floating  ice  which  lodged  on  the  beach.     The  diameter  of  the  larKest 
boulder  shown  is  about  18  inches 


■n  it.Lnsported 


leading  northeast.  It  can  be  followed  along  Sand  Ridge,  and  thence  south- 
east to  the  steep  bluff  at  the  head  of  Illinois  River,  where  later  erosion  has 
eliminated  all  trace  of  it.  East  of  this  p(jint  it  can  be  observed  in  several 
places  on  the  lowland  north  of  Wilmington,  and  traced  westward,  on  the 
south  side,  it  ap]:)arently  is  coincident  with  the  heavy  dune  sand  (tt  Sand 
Ridge,  three  miles  north  of  Coal  City.  West  of  Mazon  River  it  is  again 
distinct  as  far  as  Waupecan  Creek,  where  the  narrowed  valley  precludes 
the  possibility  of  its  having  been  retained,  if  ever  formed. 

That  portion  of  the  beach  lying  in  section  20  of  W'auponsee  Town- 
ship (T.  33N.,  R.  7E.)  presents  certain  anomalous  features  which  appear 
to  demand  peculiar  controlling  conditions  in  that  area.  Here  the  beach  ridge 
is  surmounted  by,  if  it  does  not  contain  throughout,  large  boulders  of  igneous 
and  metamorphic  rocks.  The  absence  of  limestone  which  characterizes 
the  adjacent  till  suggests  a  more  distant  source  for  this  coarse  material. 
The  prominence   of   the  boulders   gradually  disappears   along  the   beach  to 


92  GEOLOGY   OF    MORRIS   QUADRANGLE 

the  east  (fig.  39),  thus  pointing  to  a  localization  of  the  controlHng  factors. 
Transportation  of  the  boulders  by  floating  ice  which  was  stranded  on  this 
part  of  the  beach  seems  to  be  the  logical  explanation  for  their  concentration 
here.  Similar  boulder  deposits  south  of  the  beach  may  have  been  made 
when  the  water  level  was  higher. 

Most  of  the  area  bounded  by  the  beach  shows  some  evidence  of  having 
been  covered  by  a  body  of  standing  water.  The  elongate  ridge  about  two 
miles  west  of  Morris,  however,  shows  no  trace  of  having  been  inundated 
at  that  time.  Its  crest  is  a  few  feet  above  540,  and  hence  may  have  been 
slightly  above  the  highest  level  of  Cryder  Lake.  The  presence  of  gravel 
and  sand  on  the  western  end  of  this  ridge  at  the  same  level  as  the  beach 
lines  north  and  south  of  the  Illinois  makes  such  an  assumption  valid. 

It  is  clear  that  drainage  conditions  obtaining  during  this  stage  were 
different  from  those  of  the  preceding  stage.  The  body  of  water  outlined 
by  the  beach  remnants  was  little  more  than  half  as  large  as  Lake  Morris. 

The  absence  of  any  extensive  deposits  comparable  to  those  made  in 
Lake  Morris  suggests  that  the  water  of  Cryder  Lake  was  able  to  transport 
most  of  the  sand  and  silt  brought  to  it.  The  character  of  the  marginal 
slope  and  of  the  bottom  of  the  basin  is  in  harmony  with  this  conception 
and  leads  to  the  inference  that  Cryder  Lake  was  little  more  than  a  widened 
river  whose  high  level  is  represented  by  the  540-foot  contour  line. 

It  is  not  improbable  that  there  was  deposition  of  limited  amounts  of 
sand  over  most  of  the  basin  of  Cryder  Lake  during  the  early  part  of  this 
stage,  the  finer  sediment  being  carried  downstream.  Maximum  deposits 
would  have  been  made  at  the  mouths  of  streams  entering  this  lake,  especially 
at  the  mouth  of  the  Chicago  outlet  in  the  DesPlaines  Valley  east  of  the 
Morris  quadrangle.  There  are  terrace  deposits  along  Waupecan  Creek  and 
Mazon  River,  as  well  as  the  smaller  tributaries  which  probably  were  con- 
temporaneous with  Cryder  Lake. 

The  further  lowering  of  the  outlet  of  Cryder  Lake  ultimately  resulted 
in  draining  it.  While  this  was  taking  place  no  further  beach  would  have 
been  formed,  and  the  540- foot  beach  would  have  been  incised  by  tributary 
streams.  Topographically,  the  resuJt  was  a  transformation  of  the  old  lake 
bottom  into  an  erosion  surface  about  15  feet  below  the  beach  with  a  rela- 
tively abrupt  slope  up  to  it.  Channel  scars  mark  the  position  of  the  later 
channels  in  the  wide  river  bottom.  The  lack  of  uniformity  in  the  altitude 
of  this  wide  flat  is  obviously  related  to  the  unevenness  of  the  bed  rock 
surface,  which  is  exposed  in  places. 

As  indicating  substages  in  this  development,  are  to  be  noted  the  rem- 
nants of  terraces  below  the  540-foot  level  along  such  streams  as  Nettle  and 
\\^aupecan  creeks.  Further  downcutting  of  this  part  of  the  Illinois  Valley 
was  restricted  to  a  relatively  narrow  strip  approximately  bisecting  the  Cryder 


HISTORICAL    GEOLOGY  93 

Lake  basin.  Evidence  as  to  the  work  done  by  this  early  river  is  concealed, 
if  not  entirely  eliminated  through  the  deposition  by  the  stream  of  the 
next  stage. 

LATER    HISTORY   OF   THE   ILLINOIS   VALLEY 

At  some  period  after  the  draining  of  Cryder  Lake  the  present  Illinois 
Valley  was  filled  to  overflowing  by  a  much  more  powerful  stream  than 
that  immediately  succeeding  the  Cryder  Lake  stage.  The  further  lowering 
of  the  outlet,  however,  may  have  caused  its  restriction  to  the  narrow  channel 
which  it  maintained.  This  stream  not  only  transported  great  volumes  of 
sand  and  coarse  gravels  from  the  DesPlaines  gravel  beds  above  Channahon 
but  also  was  apparently  able  to  scour  the  previously  existing  channel.  It 
seems  to  have  maintained  a  wide  but  shallow  channel  in  its  course  over  the 
exposed  rocks  above  and  just  below  the  head  of  Illinois  River.  It  is  not 
impossible  that  these  knolls  of  limestone  and  sandstone  remained  as  islands 
in  the  streams  most  of  the  time,  while  the  circuitous  channels  outlined  by 
the  gravel  deposits  of  this  stage  were  incised.  (See  Plate  II.)  Downstream, 
however,  the  relative  weakness  of  the  Carbondale  formation  permitted  deeper 
and  more  concentrated  erosion.  The  bed  rock  conditions  east  of  Morris 
are  such  as  might  readily  have  caused  the  development  of  prominent  rapids 
in  the  postulated  stream  as  it  passed  from  the  resistant  Pottsville  to  the 
weaker  Carbondale  strata.  It  appears  probable  that  at  the  stage  of  maxi- 
mum volume,  waters  were  ponded  in  the  shallow  depressions  adjoining  the 
main  channel  of  this  date,  and  that  under  these  conditions  were  deposited 
the  sand,  marl  and  peat  beds  in  the  area  just  north  of  Morris  revealed 
in  Bell's  stripping  pit  in  sec.  34,  T.  34  N.,  R.  7  E.  The  great  volume 
of  the  stream  is  attested  by  the  depth  of  the  erosion  as  well  as  by  the  amount 
and  character  of  the  deposits,  but  more  clearly  still  by  the  low  gradient 
which  it  appears  to  have  maintained.  By  the  time  this  powerful  stream  was 
somewhat  reduced  the  pre-existing  surface  had  been  incised  to  a  maximum 
depth  of  perhaps  35  feet.  With  further  reduction  of  volume,  not  only  this 
channel  but  the  adjacent  less  eroded  lowlands  were  concealed  by  deposits  of 
sand  and  gravel.  It  was  at  this  time  that  the  prominent  gravel  and  sand 
deposits  at  the  520-foot  level  bordering  the  flood  plain  of  the  present  Illinois 
were  laid  down.  The  undulatory  character  of  the  surface  and  the  "pockety" 
nature  of  the  gravel  and  sand  beds  reveal  their  origin  in  sand  and  gravel 
bars  in  the  bed  of  this  ancient  river.  With  the  further  reduction  of  its 
volume,  maximum  deposition  by  this  stream  was  made  farther  and  farther 
upstream  above  the  head  of  Illinois  River. 

The  next  step  in  the  development  of  the  topography  of  the  Morris 
Basin  was  the  restriction  of  the  active  stream  to  the  relatively  narrow  channel 
which  it  occupies  now.     Coincident  with  this   was  an  increase  in  erosive 


94  GEOLOGY   OF    MORRIS   QUADRANGLE 

power  which  resulted  in  the  development  of  a  shallow  trench  within  the 
sand  and  gravel  flat.  A  temporary  increase  in  volume  is  the  most  probable 
cause  of  this  incision.  This  was  followed  by  a  reduction  in  volume  and 
consequent  deposition  within  the  trench  and  at  this  time  the  present  stage 
in  the  history  of  the  Illinois  opened.  With  the  later  development  of  the 
tributaries  in  the  headwater  areas,  the  amount  of  water  coming  down  the 
Kankakee  and  the  DesPlaines  has  been  increased  gradually.  Corresponding 
to  this  change  there  has  been  more  and  more  transportation  of  material. 
Only  the  fine  sand  and  silt  from  the  drainage  area  is  being  brought  down, 
however,  and  the  development  of  the  rich  flood  plain  lands  bordering  the 
Illinois  in  the  Morris  quadrangle  has  resulted.  That  this  alluvial  filling  is 
only  a  thin  coating  over  the  gravels  of  the  preceding  stage  is  evident  from 
all  pits  and  borings  made  over  the  flood  plain. 


CHAPTER  VI— ECONOMIC  GEOLOGY 

The  foregoing  discussion  of  the  various  geologic  features  of  the  Morris 
quadrangle  serves  as  the  basis  for  a  description  of  the  economic  resources 
of  the  region.  Without  such  basis  the  discussion  of  mineral  wealth  can  be 
little  more  than  a  catalog  of  known  resources  without  reference  to  their 
vertical  and  areal  extent  and  without  guidance  for  further  exploration. 
With  their  relations  revealed  by  a  study  of  the  stratigraphy,  however,  the 
restriction  of  coal,  limestone,  sand  and  gravel  to  certain  areas  is  clear,  and 
the  size  and  shape  of  known  bodies  of  useful  materials  as  well  as  the  probable 
character  of  similar  material  yet  undiscovered  may  be  fairly  estimated. 

Coal,  shale  and  clay,  stone,  sand  and  gravel,  as  well  as  water  and  soils, 
comprise  the  known  resources,  which  will  be  discussed  in  the  order  given. 
Brief  reference  will  be  made  also  to  the  possibility  of  finding  oil  in  the  area, 
although  oil  is  not  known  at  the  present  time  to  exist  here  in  commercial 
quantity. 

Coal 

general  relations 

The  Morris  quadrangle  lies  at  the  northeast  edge  of  the  Eastern  Interior 
Coal  Basin,  the  great  coal  field  which  includes  most  of  Illinois  and  parts 
of  states  adjoining  on  the  east,  south  and  west.  Disregarding  the  com- 
mercially unimportant  outliers  of  this  portion  of  the  field,  the  border  of  the 
basin  crosses  the  quadrangle  in  an  irregular  line  trending  northwest-southeast 
a  few  miles  northeast  of  the  town  of  Morris.  The  entire  (juadrangle  south- 
west of  this  line  is  probably  underlain  by  one  or  more  beds  of  workable  coal. 

That  portion  of  the  quadrangle  underlain  by  No.  2  coal  in  commercial 
thickness  is  included  in  what  is  known  as  the  Longwall  District,  a  sub- 
division of  the  coal  fields  of  Illinois  and  given  that  designation  from  the 
prevailing  method  of  mining.  This  district  includes  part  or  all  of  Bureau, 
Putnam,  Marshall,  La  Salle,  Livingston,  Grundy,  Will  and  Kankakee  counties. 

The  only  coal  of  the  area  commercially  important  at  the  present  time 
is  No.  2  bed,  which  outcrops  just  northeast  of  Morris  and  underlies  the 
southwestern  part  of  the  quadrangle.  This  coal  marks  the  base  of  the 
Carbondale  formation  and  hence  lias  stratigraphic  as  well  as  economic  im- 
portance. Thin  coals  are  known,  both  from  outcrop  and  exploration,  above 
and  below  No.  2,  but  none  so  far  discovered  warrants  development. 

95 


96  GEOLOGY   OF    MORRIS   QUADRANGLE 


POTTSVILLE    COALS 


The  coals  of  the  Pottsville  series  have  not  been  widely  explored,  but 
such  openings  on  them  as  have  been  made  indicate  that  there  are  car- 
bonaceous beds  at  several  horizons.  These  show  varied  development,  in 
places  being  merely  a  thin  streak  of  carbonaceous  material  while  elsewhere 
several  feet  of  coal  may  appear  (fig.  24). 

As  noted  in  the  discussion  of  the  stratigraphy  of  the  region,  the  coal 
uncovered  in  stripping  for  the  clay  pit  at  the  west  end  of  Goose  Lake  is 
considered  to  be  a  bed  lying  below  No.  2  coal.  The  details  of  this  section 
were  included  in  the  earlier  discussion  (p.  46).  This,  or  a  similar  bed,  was 
opened  as  a  country  bank  a  few  rods  southeast  of  the  pit  many  years  ago 
and  essentially  the  same  section  was  reported.  It  is  probable  that  the  full 
thickness  of  the  coal  bed  is  somewhat  greater  than  the  section  shows,  although 
no  openings  to  the  south,  down  the  dip,  have  been  made.  Further  develop- 
ment may  reveal  not  only  a  greater  thickness  of  coal,  but  the  presence  of 
roof  shales  as  well.  Plant  fossils  in  these  shales  may  render  the  exact  correla- 
tion of  this  coal  possible. 

The  bed  of  coal  worked  in  the  two  shafts  in  section  19  of  Aux  Sable 
Township  (T.  34  N.,  R.  8  E.)  apparently  has  the  same  stratigraphic  posi- 
tion as  the  Goose  Lake  coal.  It  was  28  inches  thick,  with  variable  roof  and 
had  only  a  limited  extent.  Bradley  did  not  consider  the  evidence  sufficiently 
clear  to  permit  correlation.^^  No  other  openings  are  known  to  have  been 
made  on  Pottsville  coals,  nor  were  these  of  more  than  local  importance. 
Such  beds  have  been  reported  in  some  borings,  as  in  the  case  of  the  well 
at  Braidwood^-  just  east  of  the  IMorris  quadrangle,  where  three  coals  were 
encountered  in  the  60  feet  of  Pottsville  sediments.  There  is  no  indication 
that  the  coals  below  No.  2  have  any  better  development  south  of  the  edge 
of  the  Pennsylvanian  basin  than  where  they  have  been  encountered. 

Carbondale  Coals 

NO.    2    COAL 

This  bed  is  widespread,  of  remarkably  uniform  thickness  and  character 
and  has  been  mined  in  scores  of  openings.  The  presence  of  this  coal  in 
workable  thickness,  is  the  basis  for  delimiting  the  Longwall  District  in 
this  State.  It  underlies  all  of  the  quadrangle  south  of  its  outcrop  except 
possibly  the  valley  of  the  Illinois  above  Morris.  While  the  heavy  drift 
cover  prevents  exact  delineation  of  the  outcrop,  its  approximate  location  is 
shown  on  Plate  III,  thus  indicating  the  contact  of  Pottsville  and  Carbondale 
formations. 


siBradley.  Frank  H.,  Geol.  of  111.,  Vol.  IV.  p.  198,  1870. 
'-Log  furnished  by  Mr.  William  Campbell  of  Coal  City. 


97 


As  thus  mapped  about  115  square  miles  are  underlain  by  the  Carbon- 
dale  formation.  In  the  estimate  of  available  tonnat^e  from  No.  2  coal  in 
this  region  there  must  be  considered  (1)  the  variation  in  thickness  of  the 
bed,  (2)  the  area  which  is  unworkable  by  shaft  mining  because  of  poor 
roof  and  (3)  the  area  already  mined  out.  The  lack  of  reliable  data  on 
these  points  renders  more  than  a  rough  approximation  of  the  tonnage  im- 
practicable. 

While  there  are  few  borings  penetrating  No.  2  coal  in  that  part  of 
the  quadrangle  lying  west  of  Mazon  River,  the  uniformity  in  thickness  of 
the  bed  in  the  vicinity  of  Coal  City  and  in  the  region  south  of  Seneca  leads 
to  the  inference  that  No.  2  is  present  in  average  thickness  in  the  interven- 
ing area.  That  part  of  the  bed  which  is  overlain  by  a  poor  roof  is  probably 
restricted  to  a  strip  ])arallel  to  the  outcrop,  and  approximately  two  miles 
wide.  This  would  eliminate  between  thirty  and  forty  scpiare  miles  from  the 
field  available  for  shaft  mining.  It  is  probable  that  a  considerable  portion 
of  this  tonnage  is  recoverable,  however,  by  stripping  operations,  which  thus 
compensate,  or  partly  compensate,  for  the  assumed  loss. 

Figures  for  the  total  production  of  this  area  are  in  error  by  an  un- 
known percentage  and  in  any  case  serve  only  as  a  guide  in  this  estimate, 
since  for  every  ton  of  coal  reported  as  mined  it  is  probable  that  approxi- 
mately a  half  a  ton  has  been  rendered  unfit  for  mining.  Estimate  of  this 
factor  by  calculation  of  the  area  involved  in  operations  of  the  known  mines 
gives  a  figure  of  about  twenty  square  miles.  From  the  original  estimate 
of  115  square  miles  there  is  thus  to  be  deducted  about  fifty  square  miles. 
Assuming  an  average  thickness  of  30  inches,  the  remaining  sixty-five  square 
miles  contain  about  183,000,000  tons. 

Physical  character. — No.  2  bed  is  characterized  by  the  alternation  of 
dull  and  bright  bands  of  clean  coal  without  persistent  bands  of  impurities. 
Thin  plates  of  calcite  commonly  are  seen  on  vertical  faces.  Pyritic  lenses. 
"bone"  or  shale  bands  and  charcoal  or  mining  dirt  separate  the  clean  coal 
bands,  but  these  impurities  are  small  in  amount  and  so  irregularly  disposed 
that  the  bed  as  a  whole  shows  no  benches.  The  pyritic  iiupurities,  such 
as  "sulphur  balls,"  are  not  readily  separated  from  the  coal  and  hence  some 
coal  is  lost  in  separating  the  pyrite.  In  the  deeper  openings  the  coal  is 
relatively  hard  and  brittle,  the  top  coal  being  harder  than  the  bottom  and  in 
most  places  of  brighter  luster.  "Cleat"  is  nowhere  well  developed.  In  the 
shallower  workings  the  coal  is  relatively  soft  and  shows  less  difference  in 
hardness  and  texture  between  top  and  bottom. 

Chemical  composition. — The  chemical  character  of  No.  2  coal  is  fairly 
well  established  for  tlic  Morris  region,  although  but  few  samples  from  the 
openings  within  the  quadrangle  have  been  analyzed.  The  average  for 
Grundv  Countv  shows  a  high  moisture  content  with  medium  sulphur  and 


98 


r.EOLOGY    OF    MORRIS    QUADRANGLE 


low  ash.    Determinations  of  heating  value  show  an  average  of  almost  11,000 
B.  t.  u.  on  the  "as  received"  basis. 

In  the  appended  list  are  presented  all  the  available  analyses  of  No.  2 
coal  from  the  Morris  quadrangle.  These  were  made  for  the  State  Geological 
Survev  under  the  direction  of  Professor  S.  W.  Parr. 


T 

ABLE    6 / 

^roximate 

analyses  o 

f  'No.  2  coal  from  Morris  Quadrangle 

Labor- 
atory  No. 

Form"  of 
Analysis 

Mois- 
ture 

Volatile 
matter 

F"ixed 
carbon 

Ash 

Sulphur 

Carbon 
as  CO2 

British 
thermal 

units 

2624 

A 

17.56 

35 .  63 

36.19 

10.62 

1.70 

10200 

B 

43.22 

43.90 

12.88 

2.06 

12373 

5367 

A 

19  97 

38.16 

37.45 

4  42 

1   82 

.65 

10936 

B 

47.68 

46.79 

5.53 

2.27 

.79 

13664 

5368 

A 

18  95 

37.60 

38.23 

5.22 

2.46 

.64 

10787 

B 

46  39 

47.16 

6.45 

3.04 

.79 

13309 

5369 

A 

19.66 

37   01 

38.16 

5.17 

2.03 

.83 

10734 

B 

46.06 

47 .  50 

6.44 

2.53 

1.03 

13360 

260Q 

A 

13.24 

36.44 

39.04 

11.28 

5.42 

10764 

B 

42.00 

44.99 

13.01 

6.24 

12406 

731 

A 
B 

A 

14.16 

5.00 

5.82 

5.68 

1.57 
1.83 

2  36 

11531 

13436 

4391 

16  43 

36.64 

41   25 

11089 

B 

43.84 

49.37 

6.79 

2.83 

13269 

4392 

A 

14.50 

38.62 

41.12 

5.76 

2.27 

.40 

11196 

B 

45.17 

48.10 

6.73 

2.66 

.47 

13095 

5373 

A 

17.29 

38.61 

36.69 

7.41 

2.87 

1.44 

10708 

B 

46.68 

44  36 

8.96 

3.47 

1.74 

12947 

5374 

A 

13.73 

39.87 

42.19 

4  21 

2.04 

1.47 

11787 

B 

46  22 

48.90 

4.88 

2.37 

1.71 

13662 

5377 

A 

17.01 

39.48 

36.74 

6.77 

3.32 

1.05 

10834 

B 

47.57 

44.27 

8.16 

4.00 

1.27 

13055 

"A — "As  received";  B — "Moisture  free." 

The  bed  varies  in  thickness  from  20  to  72  inches,  but  shows  much 
greater  uniformity  than  those  figures  indicate,  a  variation  of  less  than  5 
inches  throughout  a  mine  being  common.  Overlying  the  coal  is  gray  shale, 
commonly  40  feet  thick,  in  places  so  sandy  as  to  be  better  described  as  a 


COAL  99 

shaly  sandstone.  In  the  No.  3  mine  of  the  Big  Four  W'ihnington  Coal 
Company  a  relatively  pure  sandstone  overlies  the  coal  in  parts  of  the  mine, 
the  more  usual  shale  or  "soapstone"  coming  in  as  a  feather  edge  between 
the  sandstone  and  coal,  and  reaching  considerable  thickness  in  places.  The 
floor  is  characteristically  gray  clay,  plastic  when  wet  and  possessing  some 
refractory  properties.  It  is  an  ideal  stratum  in  which  to  undercut  the  coal 
and  is  so  utilized  in  most  workings.  It  is  invariably  called  "tire  clay,"  al- 
though its  lithologic  variation  undoubtedly  indicates  equal  variation  in  fire- 
resisting  properties.  This  clay  is  rather  uniform  in  thickness  in  a  given 
mine,  but  varies  from  a  few  inches  to  more  than  5  feet  over  the  district. 
Below  it  is  a  somewhat  gritty  shale  similar  to  the  soapstone  above  the  coal. 
In  the  mine  of  the  Braidwood  Wilmington  Manufacturing  Company  the 
5  or  6  inches  of  floor  clay  is  underlain  in  places  by  2  to  3  inches  of  coal 
with  about  4  feet  of  clay  below.  Elsewhere  the  usual  succession  obtains. 
The  following  descriptions  of  the  bed  have  been  compiled  from  notes 
by  various  members  of  the  Survey: 

BIG    FOUR    WILMINGTON   CO.\L    COMPANY,    NO.    .3,    DEWEY    SLOPE       (A,  fig.  40) 

Main  northwest  1500  feet  from  shaft.  Roof  sandstone  or  shale.  The  coal  is  36  inches 
thick,  contains  sulphur  balls  and  is  very  wet,  especially  when  first  opened  uj).  Floor 
is  fire  clay. 

BRAIDWOOD    WILMINCiTON    MANUFACTURING   COMP.\NY.       SHAFT    MINE.       (B,  fig.  40) 

Main  north  300  feet  from  shaft.  Roof  is  a  hard  soapstone  and  makes  a  good  longwall 
cover.  The  coal  is  36}/^  inches  thick  and  is  rather  wet.  The  floor  is  fire  clay  with  2  to  3 
inches  of  coal  about  5  inches  below  the  top.  Where  the  upper  clay  band  is  thick  enough 
it  is  mined  and  the  coal  wedged  down.    The  lloor  is  reported  to  heave  a  good  deal. 

CLAYTON    HROTHKRS.       MORRIS.      LOCAL    SHAFT.       (C,  fig.  40) 

Face  of  northeast  entry.  Roof  is  soapstone.  The  coal  is  38  inches  thick  with  a  local 
band  of  sulphur  and  coal  }  o  inch  thick  15  inches  from  the  top.  The  coal  is  hackly  in  fracture 
and  briltlc  in  texture.     Floor  Is  fire  clay. 

WILMINGTON    STAR    MINING    COMPANY.       No.    6    (D,   1^,  F,  (i,  fig.  40) 

Face  southwest  entry.  Roof  gray  shale  with  a  black  clay  at  base  in  places.  The  coal 
is  41  inches  thick  with  a  total  of  3  inches  of  sulj^hur  and  clay  in  three  bands.  The  5-inch 
band  of  coal  is  bright  while  the  lower  part  is  duller.  The  coal  shows  a  hackly  appearance 
on  the  whole,  is  solicl,  brittle,  and  has  no  continuous  impurities.     Floor  is  fire  clay. 

WILMINGTON    STAR    COAL   COMPANY,    MINE    NO.    7,    COAL   CITY         (H,  fig.  40) 

Face  northwest,  south  entry — roof  soapstone.  Coal  hard  and  brittle,  the  top  coal 
harder  than  the  bottom  and  in  most  places  brighter.  Cleat  poorly  and  irregularly  developed. 
The  coal  shoots  into  good-sized  blocks.  There  is  very  little  calcite  present;  near  the  middle 
of  the  bed  in  parts  of  the  mine  there  is  a  band  of  mother  coal  and  sulphur.  The  floor  is 
fire  clay  averaging  about  7  feet  in  thickness.  Undercutting  is  done  in  the  clay  to  a  depth 
of  18  to  24  inches.     Shale  is  reported  to  underlie  the  clay. 


100 


GEOLOGY   OF    MORRIS   QUADRANGLE 


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BELL  SHAFT.   MORRIS.   LOCAL 

Roof  is  soapstoiie  with  1  to  5  inches  of  clod  at  the  base.  The  contact  with  the  coal 
is  somewhat  uneven.  The  bed  is  42  to  48  inches  thick  and  contains  sulphur  lenses  and 
some  shaly  bands.  The  coal  is  soft,  of  dull  luster,  brittle  and  showing  roughly  cubic 
fracture.  The  floor  is  a  gray  fire  clay,  with  plant  impressions,  but  a  dark  gray  "slate" 
is  met  locally  where  it  cuts  out  part  of  the  coal. 

HEATHKK  SHAFT.   MORRIS.   LOCAL. 

Roof  is  soapstone  with  6  to  30  inches  of  gray  shale  or  "clod"  just  above  the  coal. 
The  contact  with  the  coal  bed  is  even.  The  coal  is  30  to  36  inches  thick  without  partings. 
Soft  "brown  sulphur"  lenses  occur  about  6  inches  from  the  top  of  the  seam.  Floor  is  a 
gray  clay,  which  makes  undercutting  easy. 

MITCHELL    SHAFT.       MORRIS.       LOCAL. 

Roof  is  soapstone  27  feet  thick.  Contact  with  coal  even.  The  bed  is  24  to  34  inches 
thick,  average  30  inches.  The  coal  is  brittle  and  mainly  of  dull  luster.  "Sulphur  balls" 
are  irregularly  distributed  but  are  not  abundant.     Floor  is  a  fire  clay. 

While  on  the  whole  the  contintiity  of  No.  2  coal  is  noteworthy,  there 
are  some  marked  deviations  that  are  of  interest  from  the  scientific  as  well 
as  the  economic  aspect.  The  prominent  "roll"  encotintered  in  No.  7  mine 
of  the  Wilmington  Star  Mining  Company  west  of  Coal  City  has  already 
heen  noted.  This  was  described  and  figured  in  an  earlier  report''''  on  this 
region  and  need  not  be  re-described  here.  Less  prominent  "rolls"  are  met 
in  most  mining  operations.  Some  of  these  appear  to  be  original  irregu- 
larities in  the  surface  of  the  swamp  in  which  vegetable  matter  accumulated. 
Others  are  clearly  due  to  intraformational  erosion  which  has  in  places  re- 
moved the  overlying  soapstone  and  even  the  upper  part  of  the  coal  bed, 
the  gap  being  later  filled  commonly  by  crossbedded  sandstone.  These  irregu- 
larities always  interfere,  often  seriotisly,  with  mining  operations.  Dislocations 
of  the  beds,  known  to  the  geologist  as  faults,  are  not  rare,  but  are  of  such 
dimensions  that  they  have  no  commercial  significance. 

COM.  IU•:n'^  AHovF   No.   2 

Throughout  the  southern  j)art  of  the  Morris  ([uadranglc  one  or  more 
coal  beds  are  found  over  No.  2  coal.  The  absence  of  stich  upper  beds 
farther  north  is,  of  course,  due  to  the  absence  of  that  part  of  the  strati- 
graphic  column.  It  is  not  clear  whether  this  lack  of  the  higher  strata  is 
because  of  non-deposition  or  because  of  erosion.  The  apparently  lenticular 
form  of  the  coal  beds,  however,  leads  to  the  inference  that  the  northern 
limit  of  the  depositional  swamps  was  south  of  Coal  City. 

With  the  exception  of  one  of  these  coal  beds,  it  is  impossible  to  make 
a  satisfactory  correlation  of   them  even   from   well  to   well.      The   reported 

"Cadv,  G.  H.,  Coal  Resources  of  District  I  (Long.vall) :    111.  Co.il  Minin;  Investigations  Ball.  10.  p.  73 
1915 


102  GEOUXJY   OF    MORRIS   OU.\riR-\XGLE 

presence  of  a  thin  coal  about  7^  feet  above  Xo.  2  over  the  area  between 
Waupecan  Creek  and  Coal  Cit\-  leads  to  the  inference  that  one  of  these 
beds  mav  fairly  be  correlated,  although  absolute  continuity-  is  improbable. 
The  one  bed  which  appears  to  be  persistent  outcrops  in  section  20  of  Wau- 
ponsee  Township  ( T.  33  X.,  R.  7E.)  on  Waupecan  Creek.  Here  it  was 
worked  at  an  early  date,  as  reported  by  Bradley,^  who  classed  it  as  Xo.  4 
coal.  This  bed  shows  a  maximum  development  of  18  inches,  but  in  most 
places  pinches  out  to  a  mere  streak  in  short  distances.  This  same  bed  was 
worked  on  Mazon  River  in  the  \-icinir\-  of  Sulphur  Springs  and  in  section  13 
of  Goose  Lake  Township  (T.  33  X.,  R,7E). 

COAL    MIXING 

E^rly  mining  in  this  region  was  on  a  small  scale.     While  some  coal 
was  taken  from  the  outcropping  beds  in  Goose  Lake,  Mazon  River  and  Wau- 


r  -z.  4'-      Reinise  damp  60  feet  high,  containing  shale  and  impure  coal  from  ni;z-r  n-ear 

pecan  Creek,  the  amount  was  insigniiicant  in  comparison  with  that  removed 
from  Xo.  2  bed,  the  operations  upon  which  will  be  noted  in  somewhat 
greater  detail. 

Strip  mines  were  operated  to  a  limited  extent,  but  most  of  the  coal  cut 
was  hoisted  through  shafts.  The  first  of  these  were  placed  about  a  mile 
back  of  the  outcrop  of  the  coal  beneath  the  drift.  Extensive  workings  were 
not  attempted,  a  new  shaft  being  sunk  as  soon  as  the  de\-elopment  from  one 
bottom  had  proceeded  a  few  hundred  feet.  This  procedure  was  necessitated 
by  the  mining  methods  in  use  which  met  drainage,  haulage  and  ventilation 
problems  by  withdrawing  from  the  field  of  operations.     When  the  most 

"Bradley.  Frank  H..  Geol.  Survey  of  ID.  VoL  FV,  p.  194.  1870. 


COAL   MIXING 


103 


favorable  sites  for  this  type  of  mining  had  been  found  and  utilized,  open- 
ings were  made  to  the  northeast  where  roof  conditions  made  operations 
uncertain  and  to  the  southwest  where  the  greater  depth  to  the  coal  increased 
operating  expenses.  But  few  shipping  mines  were  attempted  and  the  total 
production  was  not  great  from  the  early  mining  operations. 

With  the  discovery  of  thicker  coal  in  the  Braidwood  district  large  ship- 
ping mines  were  started.  These  were  profitable  and  the  employment  of  the 
longwall  system  gave  a  high  percentage  of  extraction.  The  huge  dumps  of 
shale  and  dirty  coal  which  accumulated  in  these  operations  dominate  the 
landscape  in  the  vicinity  of  Coal  City  and  indeed  constitute  the  most  promi- 
nent relief  feature  of  the  topography  (fig.  41).  Such  dumps  appear  as  far 
as  2  miles  north  of  Coal  City  and  may  be  seen  south  and  east  beyond  the 
limit  of  the  quadrangle.     In  1920.  but  one  shipping  mine  in  the  area  was 


Fis.  42.    Surface  equipment  for  local  mine.     Mitchell  shaft.  Morris 

being  worked.  This  was  the  Xo.  7  mine  of  the  Chicago,  Wilmington  and 
Franklin  Coal  Company,  and  was  located  in  section  5,  2  miles  west  of  Coal 
City.  No  shaft  has  been  sunk  west  of  this  point  and  because  of  the  expense 
involved  it  is  unlikely  that  the  coal  to  the  west  will  be  worked  in  the  near 
future.  To  supply  part  of  the  coal  demand  several  wagon  mines  are  operated 
intermittently.  Three  shaft  mines  known  as  the  Mitchell,  Heather,  and  Bell 
mines  respectively  are  located  north  and  west  of  the  town  of  Morris.  Figure 
42  illustrates  the  surface  equipment  at  the  Mitchell  shaft  which  is  typical  of 
these  operations.  Northeast  of  Morris  two  small  strip  mines  have  been 
opened.  One.  the  Bell  stripping,  is  in  the  SE.  I4  sec.  34,  and  the  other,  the 
Davidson  stripping,  is  about  one  mile  farther  east.  Figure  43  shows  the 
thickness  antl  character  of  the  till  overburden.  The  coal  was  partly  under 
water  when  this  place  was  visited. 


104 


&FOI.Or.V    OF    MORRIS    QUADRAXGI.E 


Clay  and  Shale 

As  is  usual  in  a  coal  mining  region  there  are  in  the  Morris  area  certain 
argillaceous  deposits  which  are  adapted  to  the  manufacture  of  various  clay 
products.  The  available  material,  however,  is  not  restricted  to  the  "Coal 
Measures"  but  is  found  in  beds  of  earlier  as  well  as  later  origin. 

ORDOVICL\N  shale 

The  Upper  Ordovician  section  includes  a  shale  member,  the  Maquoketa, 
which  is  quite  uniformly  about  60  feet  thick  and  which  outcrops  beneath  the 
drift  in  the  belt  mapped  on  Plate  III.  No  surface  exposures  of  this  forma- 
tion occur,  however,  and  the  drift  and  bed  rock  cover  may  be  too  thick  for 


Fig.  4.^.     \ir\v  of  siiu'.ll  strip  pit  nortluast  of  ,\'orris.     Note  l:oiil(li  rs  in  till  of  the  cj\-crluirdcn 


any  but  large  scale  operations.  No  tests  have  been  made  to  ascertain  the 
quality  of  this  shale,  which  appears  from  drill  cuttings  to  be  free  from  grit 
or  other  impurities.  Tests  made  on  samples  from  the  weathered  portion 
of  this  formation  in  southwestern  Wisconsin  show  it  to  be  but  slightly  cal- 
careous. It  was  there  recommended  for  hollow  ware  and  probably  is  suit- 
able for  paving  brick  though  not  in  any  sense  a  refractory  material.  It  is 
likely  that  similar  results  would  be  obtained  from  tests  of  the  IVIaquoketa 
of  Grundy  County. 

PENNSYLVANIAN  SHALE 

From  the  Pottsville  formation  of  the  Pennsylvanian  strata  certain 
shales  have  been  found  adaptable  to  several  uses.  Such  beds  lie  beneath  the 
coal  at  Jugtown  in  sec.  16,  T.  33  N.,  R.  8  E.,  and  are  now  being  worked  by 
the  Haeger  Brick  and  Tile  Company  at  the  west  end  of  Goose  Lake.     Strati- 


CLAY    AND    SHAI.E  105 

graphically  these  lie  high  in  the  Pottsville  and  perhaps  are  to  be  correlated 
with  the  clays  mined  at  Rock  Island.  Colchester,  and  other  places  in  the 
western  part  of  the  State.  \\  hile  the  Jugtown  clays  are  not  known  to  he 
refractory,  some  of  those  of  the  Goose  Lake  depression  are.  In  fact,  tests 
made  show  that  some  of  the  shales  compare  very  favorably  with  the  best  fire 
clays  of  the  State.  For  that  reast)n  the  Goose  Lake  clays  are  worthy  of  more 
than  ])assing  notice. 

Even  a  cursory  examination  of  this  old  lake  basin  shows  that  the  strati- 
graphic  relations  are  not  simple.  Three  outstanding  factors  combine  to 
produce  the  irregularities  observed.  There  is  first  the  basin's  relief,  which 
though  low  is  still  efi'ective  in  producing  an  intricate  areal  pattern  in  the 
slightly  dipping  l)eds  of  the  area.  As  a  second  factor  there  is  the  warping 
of  the  beds  themselves  which  gives  great  variety  to  the  general  southward 
dip  of  the  formation.  Thus  there  are  at  the  clay  pit,  at  the  west  end  of  the 
former  lake,  beds  dipping  about  10  degrees  south.  Farther  west  these  beds 
dip  southeast  about  1  degree  and  to  the  north  they  are  dipping  almost  imper- 
ceptibly northward.  In  many  parts  of  the  basin  the  structure  is  not  revealed 
by  the  outcrops  and  indeed  the  extent  to  which  the  recorded  dip  measures 
original  inclination  rather  than  warping  is  not  known.  The  effect  of  the 
attitude  of  the  beds,  however,  is  to  increase  the  complexity  of  their  areal 
pattern.  A  third  important  factor  is  the  lenticular  character  of  the  beds 
themselves.  This  is  shown  by  the  variation  in  the  section  from  place  to  place 
as  revealed  by  excavations  and  drilling.'"  llius  the  sandstone  encountered 
in  the  Haeger  clay  pit  is  distinctly  lenticular.  The  coal,  which  is  there  about 
60  inches  thick,  appears  to  be  about  24  inches  thick  a  few  rods  distant.  Other 
stringers  of  coal  from  1  inch  to  6  inches  thick  can  not  be  correlated  from  one 
test  hole  to  another.  In  the  same  way  the  shales  of  the  section  appear  to  be 
lenticular.  As  yet  sufificient  work  on  either  the  extent  of  the  shale  beds  or 
their  refractory  properties  has  not  been  done  to  delimit  accurately  the  area 
underlain  by  fire  clay.  It  is  clear,  however,  that  near  the  center  of  the  lake 
basin  some  of  the  outcropping  shales  are  distinctly  refractory.  One  sample 
sent  in  to  the  Ceramics  Department  of  the  University  of  Illinois  gave  high 
tests,^"  fusing  with  cone  31  at  a  temperature  of  1750°C\  or  3182° F.  This  is 
a  No.  1  fire  clay  and  on  the  basis  of  its  behavior  when  mixed  with  water 
would  be  classed  as  a  semi-flint  clay.  As  noted  above,  however,  field  data 
at  hand  do  not  make  clear  the  extent  of  the  area  underlain  by  the  more  valu- 
able deposits  of  refractory  .shale. 

In  the  rocks  stratigraphically  over  the  Pottsville  deposits  just  men- 
tioned there  occur  similar  shale  and  sandy  shale  beds  which  should  be  listed 
in  a  catalog  of  the  clay  and  shale  resources  of  the  area. 


"^The  writer  gratefully  acknowledges  his  obligation  to  Mr.  E.  H.  \'an  Schoick  of  Chicago  Retort  and 
Fire  Brick  Company,  Ottawa,  for  data  on  the  drilling  tests  made  in  the  Goose  Lake  basin. 
^^Parmelee,  C.  W.,  Personal  communication. 


106  GKOi.o;;v  of  morris  quadrangle 

The  "soapstone"  roof  of  No.  2  coal  is  in  most  parts  of  the  quadrangle 
a  slightly  gritty  shale.  In  places  it  is  very  sandy  but  more  frequently  it  is 
a  clean  shale.  This  is  adapted  to  the  manufacture  of  brick  and  drain  tile 
although  not  mined  with  the  coal  for  that  purpose.  A  vast  accumulation  of 
this  material,  more  or  less  mixed  with  coaly  matter  and  pyrite,  is  found  in 
the  prominent  mine  dumps  of  the  Coal  City  area.  That  this  is  available  for 
the  making  of  drain  tile  has  been  demonstrated  by  the  commercial  tests  made 
by  the  Haeger  Brick  and  Tile  Company  of  Coal  City. 

It  is  not  known  exactly  what  deposits  were  used  at  Jugtown.  Without 
doubt  they  belonged  to  the  Pennsylvanian  which  comes  practically  to  the 
surface  in  that  vicinity.  Whether  the  shales  used  were  lying  above  or 
below  the  coal  is  not  known  but  these  may  have  been  just  below  what  is 
considered  No.  2  coal.  No  tests  on  the  refractory  properties  of  this  shale 
have  been  reported,  hence  it  is  not  likely  a  high  grade  fire  clay. 

There  are  in  the  upper  part  of  the  Carbondale  formation  other  shales 
which  vmdoubtedly  have  properties  rendering  them  suitable  for  brick  and 
tile  manufacture  at  least,  but  no  attempt  to  test  them  out  has  been  reported. 
Such  beds  are  found  below  the  Waupecan  sandstone  and  farther  down  in 
the  formation  as  exposed  on  Mazon  River  in  the  vicinity  of  Claypool  Ditch. 

PLEISTOCENE    CLAY 

Still  younger  in  age  and  of  different  origin  are  the  deposits  referable 
to  the  Pleistocene  or  Glacial  epoch.  Two  of  these  are  being  worked  and 
the  presence  of  other  deposits  of  similar  character  is  to  be  expected.  The 
older  of  the  two  comprises  the  finely  laminated  lake  clays  on  the  East  Fork 
of  Nettle  Creek  in  Morris  and  which  are  worked  at  the  Morris  Tile  Factory. 
The  deposit  now  worked  is  of  rather  limited  areal  extent,  being  restricted  to 
an  erosional  depression  in  the  surrounding  Pennsylvanian  sandstone.  This 
deposit  is  a  remnant  of  a  rather  extensive  series  of  beds  laid  down  in  a 
glacial  lake  of  pre-Marseilles  age.  Most  of  the  original  material  has  since 
then  been  removed  by  glacial  and  stream  erosion.  In  protected  places,  how- 
ever, remnants  may  be  found. 

These  clays  have  long  been  used  for  brick  and  drain  tile  which,  if 
properly  made,  appear  to  be  entirely  satisfactory.  For  further  discussion  of 
these  beds  the  reader  is  referred  to  the  chapter  on  Descriptive  Geology 
(pp.  .S8-59). 

The  other  Quaternary  deposit  is  glacial  clay,  or  till,  a  deposit  made  by 
the  ice  directly  without  the  intervention  of  water  to  an  appreciable  extent. 
This  material,  while  present  over  all  of  the  quadrangle,  is  in  most  places 
so  filled  with  cobbles  and  boulders  as  to  be  unavailable  as  clay.  Locally  it 
;S  essentially  free  from  boulders  and,  as  at  Coal  City,  becomes  a  source  of 
raw  material  for  brick  and  tile.     Much  of  the  ground  moraine  area  south 


107 


of  Illinois  River  above  the  560-foot  level  may  include  workable  beds  similar 
to  that  at  Coal  City. 

In  early  times  brick  and  drain  tile  were  made  from  all  the  types  of 
deposits  noted.  In  addition  a  rough  type  of  pottery  was  manufactured  at 
Jugtown  from  the  Pennsylvanian  shales.  No  other  such  operation  has  been 
reported  from  this  area. 

At  present  no  pottery  is  being  made  and  but  two  plants  for  brick  and 
tile  are  in  operation.  The  outlook  for  the  future,  however,  includes  the 
preparation  of  ground  fire  clay  from  the  Goose  Lake  beds  and  operations 
looking  to  the  establishment  of  this  industry  are  already  under  way. 

Stone 

Both  sandstone  and  limestone  are  available  for  structural  work.  The 
former  has  been  used  to  only  a  very  limited  extent,  and  the  latter  very 
considerably. 

The  sandstone  is  of  Pottsville  age  and  that  which  was  quarried  out- 
crops just  east  of  the  Morris  quadrangle  between  DesPlaines  and  Kankakee 
rivers.  Ponds  of  regular  shape  mark  the  sites  of  the  early  excavations, 
and  piles  of  dimension  blocks  reveal  the  character  of  the  product,  a  soft 
stone  of  light  color  and  of  medium  coarse  grain.  It  was  readily  worked  but 
probably  the  amount  of  water  encountered  was  a  serious  obstacle  to  quarry- 
ing.    No  other  sandstone  quarry  in  the  quadrangle  is  recorded. 

The  Galena  dolomite  of  Middle  Ordovician  age  was  similarly  used  for 
construction  at  an  early  date.  A  few  churches  and  schools  in  the  region 
were  built  entirely  of  this  stone  and  more  commonly  it  served  for  barns  and 
foundations.  For  such  purposes  the  old  Lisbon  quarry,  as  well  as  one  in 
section  34  of  the  same  township  and  another  in  section  24  of  Saratoga  town- 
ship (T.  34  N.,  R.  7  E.)  Grundy  County,  were  originally  opened. 

While  undoubtedly  available  for  such  use,  the  bufif  weathering  of  the 
stone  renders  it  unattractive  and  there  has  been  little  reason  for  continuing 
the  expensive  operation  of  quarrying  and  cutting.  As  a  result  the  quarry- 
ing now  is  carried  on  solely  for  the  preparation  of  road  material  and  an 
increasing  mileage  of  crushed  stone  roads  is  being  laid  out.  Lisbon  Town- 
ship owns  the  quarry  site  in  section  21  and  this  is  in  operation  from  time 
to  time  as  road  material  is  needed. 

The  importations  of  crushed  dolomite  from  the  large  quarries  at  Joliet 
have  made  impracticable  the  opening  of  other  quarries  in  the  quadrangle. 
The  use  of  the  Galena  dolomite  as  a  fertilizer  to  correct  soil  acidity  has  not 
been  attempted.     Laboratory  tests  •'"  indicate  a  high  neutralizing  power  for 

"Tests  made  by  Mr.  Victor  E.  Spencer  of  the  Agronomy  Department,  University  of  Illinois,  on  samples 
of  both  Galena  and  Maquoketa  limestones  submitted  by  the  writer. 


108  GEOLOGY    OF    MORRIS    QUADRANGLE 

this  rock  and  large  scale  experiments  are  suggested.  Another  Hmestone,  the 
Maquoketa,  which  outcrops  in  the  eastern  part  of  the  quadrangle  is  also  of 
such  purity  as  to  be  excellent  for  application  to  acid  soils.  Because  of  the 
interbedding  of  argillaceous  strata  with  the  limestone  in  Aux  Sable  Valley 
and  the  topographic  position  of  the  beds  along  the  Illinois,  large-scale  opera- 
tions are  probably  impracticable.  As  a  local  supply,  however,  such  beds 
should  be  considered,  since  laboratory  tests  show  this  rock  to  have  high 
neutralizing  power. 

A  third  source  of  fertilizer  of  this  same  type  is  found  in  the  Quaternary 
deposits  near  Morris.  In  the  overburden  removed  from  the  coal  at  Bell's 
stripping  in  the  swamp  area  in  section  34  of  Sanitoga  Township  (T.  34  N., 
R.  8  E.),  there  is  a  stratum  of  shell  marl  of  such  purity,  thickness,  and  posi- 
tion as  to  be  readily  available  for  use  as  fertilizer.  Its  unconsolidated  state 
renders  it  unnecessary  to  crush  or  otherwise  prepare  it  for  use,  so  that  a 
limited  supply  is  immediately  available.  The  origin  of  this  deposit  leads  to 
the  inference  that  it  is  not  widespread  and  since  it  has  an  average  thickness 
of  less  than  one  foot  it  is  believed  that  this  will  never  be  other  than  a  supply 
to  meet  local  needs. 

Sand  and  Gravel 

All  deposits  of  these  materials  are  of  Pleistocene  age.  They  comprise 
outwash  deposits  from  the  receding  ice  sheets  and  terrace  deposits  of  fluvial 
origin.  While  restricted  to  certain  belts,  these  deposits  are  sufficiently 
abundant  to  supply  all  the  needs  of  the  area  for  an  indefinite  period. 

The  main  deposits  lie  within  the  old  valley  walls  of  the  Illinois  and  are 
found  up  to  an  elevation  of  about  525  feet.  Local  gravel  pits  line  the  valley 
on  both  sides  of  the  river  and  are  found  in  some  of  the  tributary  depressions 
as  well.     The  sites  of  many  of  these  pits  are  shown  on  Plate  II. 

In  composition  the  gravels  are  similar  to  those  of  the  DesPlaines  Valley, 
but  are  finer  with  a  greater  proportion  of  sand.  Because  of  the  proximity 
of  the  extensive  DesPlaines  gravels,  the  utilization  of  their  downstream 
equivalents  has  been  strictly  local.  They  are  available  for  both  gravel  and 
concrete  road  construction  but  because  of  the  lenticular  character  of  the 
deposits  are  expensive  to  work. 

Aside  from  the  beds  within  the  main  valley  there  are  smaller  related 
deposits  along  the  major  tributaries.  Typical  of  these  are  the  pits  in  sec- 
tions 7  and  18  of  Aux  Sable  Township  (T.  34  N.,  R.  8  E.)  along  Walley 
Run  and  Aux  Sable  Creek. 

Still  another  type  is  that  found  in  the  recessional  moraines  in  the  north- 
west part  of  the  quadrangle.  These  comprise  ill-assorted  material  including 
gravel,  sand,  and  clay  in  varied  proportions.  The  deposit  opened  in  section 
31  of  Lisbon  Township  (T.  35  N.  R.  7  E.)  is  one  of  this  type.    The  material 


109 


is  available  for  road  building  but  is  not  clean  enough  for  other  uses  to  which 
sand  and  gravel  are  commonly  put. 

Water 

The  water  resources  of  this  area,  while  not  in  themselves  of  commer- 
cial importance  are  indirectly  of  the  greatest  importance  in  the  industrial 
development  of  the  region. 

The  Morris  quadrangle,  like  the  area  surrounding  it,  is  abundantly 
supplied  with  water.  While  in  practically  all  cases  it  is  "hard"  water  and 
in  many  it  is  a  "sulphur"  water  as  well,  still  the  needs  of  the  inhabitants 
are  adequately  supplied.  In  the  vicinity  of  Sulphur  Springs  there  are  three 
wells  from  which  a  relatively  "soft"  water  issues.  The  logs  are  not  avail- 
able and  the  horizon  of  the  supply  is  not  known.  It  is  presumably  some 
Pennsylvanian  sandstone.  Intermittent  springs  are  common  but  are  little 
used  except  for  stock.  Permanent  springs,  on  the  contrary,  are  not  com- 
mon. One  of  the  largest  in  the  vicinity  lies  a  short  distance  west  of  the 
({uadrangle  in  Nettle  Creek  Township.  This  is  a  remarkably  cold  water 
from  which  bubbles  of  marsh  gas  continually  emerge. 

Shallow  wells,  by  which  are  meant  those  which  do  not  penetrate  the 
bed  rock,  are  very  common.  In  the  valley  of  Illinois  River  below  the  540- 
foot  level  such  wells  commonly  reach  an  abundant  supply  at  depths  of  less 
than  20  feet.  Such  a  well  is  that  in  the  northeast  quarter  of  section  33  of 
Saratoga  Township  ( T.  34  N.,  R.  7  E.)  less  than  a  mile  north  of  Morris.  One 
of  the  deeper  surface  wells  is  that  recently  drilled  at  the  Stein  School  1^ 
miles  southeast  of  Morris  where  a  good  supply  of  water  was  found  at  64 
feet,  probably  but  a  few  feet  above  the  Pennsylvanian  sandstone.  Outside  of 
the  main  valley  the  depth  of  the  wells  varies  from  place  to  place,  the  deepest 
surface  wells  being  in  the  northeast  part  of  the  quadrangle  wlierc  the  drift 
is  thick.     Here  reported  depths  of  100  feet  are  not  rare. 

While  these  wells  in  surficial  material  are  found  througliout  the  quad- 
rangle, the  search  for  water  below  the  bed  rock  has  been  ])rosecutcd  sys- 
tematically for  two  reasons.  First,  because  it  is  believed  that  the  chance  of 
contamination  is  less,  and  second,  because  the  deeper  wells  are  usually 
artesian  and  the  supply  is  more  constant.  While  the  artesian  pressure  is  fre- 
(juently  not  sufficient  to  produce  a  surface  flow,  or  if  produced  at  first  not 
long  maintained,  the  pumping  required  is  much  less  than  that  for  water  from 
shallower  wells.  These  deeper  wells  are  drilled  to  depths  which  vary  notably 
for  several  reasons. 

Dififerences  in  topography  make  obvious  dit¥erences  in  the  depth  at  which 
water  will  be  found.  A  second  factor  is  the  position  within  the  quadrangle. 
Plate  I  shows  clearly  that  a  given  water-bearing  stratum,  as  the   St.  Peter 


110  GEOLOGY    OF    MORRIS    QUADRANGLE 

sandstone,  lies  at  greater  depth  toward  the  southeast  part  of  the  quadrangle. 
A  third  factor  is  the  variation  in  the  formations  themselves.  Thus  a  boring 
may  meet  a  fair  supply  of  water  at  100  feet  within  the  Galena  formation 
while  a  well  nearby  may  have  to  be  sunk  200  feet  in  the  same  formation 
before  finding  any  water.  Similarly  in  the  Pennsylvanian  series  a  porous 
water  yielding  sand  in  one  place  may  correspond  stratigraphically  to  an 
impervious  shale  nearby. 

As  a  rule  the  water  from  the  deep  wells  is  hard  and  those  penetrating  the 
"Coal  Measures"  are  more  or  less  sulphurous.  They  are  in  most  cases  very 
regular  in  supply  although  over  a  long  period  of  years  the  gradual  lessening 
in  the  flow  is  perceptible.  In  some  cases  this  is  due  to  the  failure  of  the  sup- 
ply, in  others  to  the  slow  clogging  of  pipes  with  iron  rust,  clay,  etc.  Some 
wells  have  ceased  abruptly  and  disturbance  by  blasting  or  earthquake  has 
been  assigned  as  a  cause.  The  permanence  of  the  flow  and  the  height  of  the 
water  column,  as  well  as  the  character  of  the  water,  are  closely  related  to 
the  source  of  supply. 

Drilled  wells  draw  water  from  several  formations.  In  the  southern  half 
of  the  quadrangle  many  wells  are  bottomed  in  the  Pennsylvanian  beds. 
Because  of  the  proximity  of  the  outcrop  and  the  consequently  restricted  area 
of  intake,  this  source  of  supply  is  less  reliable  than  that  next  below.  The 
common  practice  is  to  drill  for  water  in  the  upper  beds  and  if  it  is  not  found 
there,  to  continue  to  the  beds  below.  In  places  the  water  of  the  "Coal  Meas- 
ures" is  too  sulphurous  and  in  these  cases  drilling  is  usually  continued,  the 
upper  waters  being  cased  off  to  prevent  their  joining  the  purer  water  encoun- 
tered below. 

The  next  water-bearing  stratum  below  the  Pennsylvanian  rocks  is  the 
Galena  dolomite.  This  has  no  definite  water  horizon  but  is  rarely  completely 
penetrated  without  finding  a  good  water  supply.  While  uniformly  "hard" 
this  is  an  excellent  source  for  water.  More  wells  obtain  water  from  this 
stratum  than  from  any  other  in  this  area. 

Below  lies  the  St.  Peter  sandstone,  a  noted  aquifer  and  one  that  is  fre- 
quently reached  in  the  northwestern  part  of  the  quadrangle  but  rarely  else- 
where. 

The  next  water-bearing  stratum  is  in  the  Lower  Ordovician  beds  where 
the  sandstones  and  limestones  of  the  Prairie  du  Chien  formation  supply 
water  that  in  most  cases  is  abundant  but  rather  highly  mineralized.  These 
beds  have  been  tapped  but  no  well  is  known  to  give  water  from  these  beds 
at  present.  One  well  in  section  10  of  Saratoga  Township  (T.  34  N.,  R.  7  E.) 
which  is  reported  as  1,200  feet  deep  presumably  is  supplied  from  this  source 
but  the  lack  of  an  accurate  log  renders  this  uncertain.  In  this  case  the  water 
is  too  highly  mineralized  for  domestic  uses  and  a  second  well  stopped  in  the 
Galena  dolomite  furnishes  the  supply. 


SOILS  1  1  1 

A  still  deeper  supply  is  that  in  the  "Potsdam"  beds  of  Cambrian  age. 
This  has  been  reached  in  two  wells,  that  at  Minooka,  2,100  feet  deep,  and 
that  on  the  farm  of  Abe  Hoge  in  section  25  of  Nettle  Creek  Township  ( T.  34 
N.,  R.  6  E.).  This  water  was  in  both  cases  found  to  be  under  considerable 
pressure  but  was  so  highly  mineralized  as  to  be  suitable  for  stock  only. 

The  conditions  requisite  for  artesian  pressure  obtain  in  all  parts  of  the 
quadrangle  and  with  few  exceptions  the  water  in  drilled  wells  rises  many 
feet  above  the  source  stratum.  As  noted  earlier,  the  flowing  wells  are  not 
rare  although  pumping  is  frequently  resorted  to  as  a  means  of  furnishing 
an  adequate  supply.     Particularly  is  this  true  in  the  case  of  old  wells. 

Adequate  data  are  not  available  to  show  the  relative  pressures  obtained, 
but  the  water  from  the  Cambrian  beds  is  under  the  greatest  head  and  the 
shallower  wells  show  a  lower  pressure  which  roughly  corresponds  to  the 
depth  of  the  source.  At  least  one  flowing  well  has  been  reported  from  the 
drift.  This  was  drilled  in  the  valley  All  of  the  Illinois  to  a  depth  of  53  feet 
and  a  flow  of  20  gallons  per  minute  obtained.  The  Galena  was  just  pene- 
trated, however,  and  although  the  supply  was  reported  to  come  from  the 
surface  material  the  assertion  cannot  be  proved.  On  Plate  II  no  attempt 
has  been  made  to  distinguish  between  wells  having  artesian  pressure  and 
those  which  actually  flow,  since  such  distinction  would  necessitate  annual 
revision.  All  surface  wells  may  therefore  be  considered  as  non-artesian  and 
all  deep,  or  bed  rock,  wells  as  artesian. 

Some  data  as  to  the  height  of  the  water  level  in  these  wells  have  been 
obtained,  but  this,  too,  is  variable.  In  general  the  water  level  is  higher  at 
the  northwest  and  lowest  along  the  Illinois  valley,  ranging  from  about  600 
feet  above  sea  level  in  the  former  area  to  less  than  500  feet  in  the  latter. 
South  of  the  river  the  level  attained  is  about  550  feet ;  but  the  data  here  are 
few,  most  of  the  wells  not  penetrating  bed  rock.  For  details  as  to  the  supply 
and  character  of  waters  in  this  area  the  reader  is  referred  to  a  recent  report 
by  the  Survey.'''** 

Soils 

While  the  minute  differentiation  of  soils  lies  outside  the  province  of  the 
geologist  the  close  relation  between  the  geologic  events  of  a  region  and  the 
formation  of  its  soils  makes  a  review  of  the  soil  determination  of  interest. 
On  that  portion  of  the  Morris  quadrangle  lying  within  Grundy  County  many 
soil  types  have  been  mapped  as  a  result  of  a  survey  made  by  the  Illinois 
Agricultural  Experiment  Station.''''  The  Kendall  County  portion  has  not 
yet  been  mapped. 


'^Anderson,  C.  B.,  Artesian  waters  of  northeastern  Illinois:    111.  State  Geol.  Survey  Bull.  34,  1919. 
•■"Hopkins.  Cyril  G.,  et  al.,  Soil  Survey  map  of  Grundy  County. 


112  GEOLO'JV    OF    MORRIS    QUADRA  MCilK 

The  soils  reported  are  listed  below : 

1.  Deep  brown  silt  loam 

2.  Brown  silt  loam 

3.  Brown  silt  loam  on  rock 

4.  Brown  sandy  loam 

5.  Brown  sandy  loam  on  rock 

6.  Brown  sandy  loam  on  gravel 

7.  Brown-gray  silt  loam  on  light  clay 

8.  Brown-gray  sandy  loam  on  light  clay 

9.  Yellow  silt  loam 

10.  Yellow-graj'  silt  loam 

11.  Yellow-gray  sandy  loam 

12.  Yellow-gray  sandy  loam  on  gravel 

13.  Mixed  loam 

14.  Black  sandy  loam 

15.  Black  clay  loam 

16.  Peaty  loam  on  clay 

17.  Deep  peat 

18.  Muck 

19.  Dune  sand 

Areally  the  brown  silt  loam  is  the  most  important.  This,  with  the  asso- 
ciated black  clay  loam,  covers  a  large  part  of  the  quadrangle.  A  large  part 
of  the  remaining  area  is  covered  by  the  brown  sandy  loam  which  has  devel- 
oped from  the  original  till  surface  through  weathering  and  the  introduction 
of  stream  and  wind-borne  sand.  The  prominent  area  of  this  type  of  soil  is 
in  the  Coal  City  region. 

?\Iost  of  the  other  types  of  soil  are  restricted  to  the  Illinois  \'alley  where, 
as  noted  in  the  earlier  chapters,  the  geologic  events  recorded  have  produced 
areas  of  deep  sand  and  gravel,  of  bed  rock,  of  silts,  and  of  swamp  deposits. 
These  beds  give  rise  to  some  of  the  reported  soil  distinctions,  since  not  only 
the  surficial  character  but  the  sub-soil  conditions  are  considered.  Along  ihe 
stream  courses  are  found  the  upland  timber  soils,  including  yellow-gray  loams 
either  silty  or  sandy.  Where  slope  wash  is  more  prominent  yellow  silt  loam 
is  found,  the  accumulation  of  black  soils  being  prevented  by  the  constant 
removal  of  the  finer  material.  The  soil  of  the  alluvial  flats  of  the  Illinois  is 
classed  as  a  deep  brown  silt  loam,  and  is  of  such  thickness  that  the  character 
of  the  sub-soil  is  unimportant.  The  flood  plains  of  the  smaller  streams  are 
so  continually  being  added  to  frorn  various  sources  that  their  soil  covering 
's  well  classed  as  mixed  loam. 

The  undrained  areas  of  the  Cryder  Lake  basin  as  well  as  of  the  later 
drainage  courses  provide  conditions  for  the  development  of  the  peaty  or 
muck  soils  there  found.  The  dune  sand  is  of  limited  extent  and  restricted 
to  the  southeastern  part  of  the  quadrangle. 


OIL  113 

It  should  be  noted  that  the  soil  distinctions,  while  clear,  are  to  a  certain 
extent  arbitrary  and  that  in  any  classification  the  pure  types  have  undue 
prominence  while  the  more  common  gradational  types  are  relatively  incon- 
spicuous. 

In  general,  the  soils  of  the  quadrangle  are  transported  and  have  resulted 
from  the  weathering  of  a  variety  of  materials.  They  are  very  fertile  on  the 
whole,  the  poorest  lands  being  in  the  area  where  bed  rock  lies  near  the  surface. 

Oil  .    . 

In  an  examination  of  the  area  for  determination  of  the  possibilities  of 
the  presence  of  oil,  there  are  three  major  factors  to  be  kept  in  mind:  (1) 
the  presence  of  any  oil  in  the  region  in  either  large  or  small  amount,  (2)  the 
presence  of  beds  which  are  known  to  contain  oil  in  other  localities,  and  (3) 
the  presence  of  such  structures  as  favor  the  accmnulation  of  oil. 

\'ery  few,  if  any,  tests  for  oil  have  been  made  within  the  limits  of  the 
(juadrangle,  the  nearest  which  has  been  reported  being  a  few  miles  east  of 
Minooka  on  the  north  bank  of  DuPage  River.  The  only  discovery  of  oil 
of  even  small  amount  was  within  the  No.  7  mine  of  the  Wilmington  Star 
Mining  Company,  where  a  small  seepage  was  found  several  years  ago. 

Within  the  Morris  ([uadrangle  there  are  two  formations  at  least  which 
are  known  elsewhere  to  furnish  oil  in  commercial  quantity.  These  are  the 
Pennsylvanian  beds,  which  outcrop  at  the  surface  and  dij)  to  the  southwest 
beneath  a  fairly  heavy  cover  of  glacial  drift,  and  the  (Galena  dolomite,  which 
outcrops  in  the  northwest  portion  of  the  quadrangle,  and  which  is  j)rol)al)lv 
to  be  correlated  with  the  so-called  "Trenton." 

As  was  noted  in  the  chapter  on  the  structtu'al  geology  of  the  area,  the 
Ordovician  formations  may  lie  in  a  southeastward  pitching  fold  whose  axis 
runs  through  Coal  City.  As  was  i)ointed  out,  however,  because  of  the 
j)aucity  of  data  this  structure  cannot  be  considered  as  determined.  If  it 
exists  the  broad  belt  there  outlined  would  be  the  most  favorable  locus  for 
drilling. 

The  contours  on  the  surface  of  St.  Peter  sandstone,  as  represented  on 
Plate  III,  show  an  irregidarity  in  the  southwest  part  of  Saratoga  Township. 
Two  interpretations  of  the  data  were  presented  on  p.  30.  On  the  assump- 
tion that  this  irregularity  restdts  from  the  upwar])ing  of  the  Ordovician  beds, 
this  area  would  be  the  logical  place  for  testing  with  the  drill. 

With  regard  to  the  Pennsylvanian  beds,  it  is  evident  that  the  accumula- 
tion of  oil  in  commercial  ([uantity  is  not  likely  to  have  occurred  in  that  portion 
lying  within  several  miles  of  the  line  of  outcrop  since  here  the  beds  appear 
to  have  a  fairly  vtniform  southwest  ward  inclination.  Between  the  apparent 
trovigh,  southwest  of  Coal  City,  and  a  similar  but  less  marked  downward  fold 
just  west  of  the  quadrangle  lies  an  area  where  the  beds  appear  nearly  flat. 


114  GEOLOGY    OF    MORRIS    QUADRANGLE 

If  any  of  the  sandstones  here  contained  oil,  as  has  not  been  demonstrated, 
this  would  be  an  area  in  which  an  accumulation  might  be  expected. 

In  the  absence  of  any  thorough  drilling  for  this  region,  it  should  not  be 
assumed  that  there  is  no  possibility  of  oil  production,  although  as  indicated 
in  the  above  statements,  there  is  little  to  indicate  the  possibility  of  finding  oil 
in  commercial  quantity. 


STATE    GEOLOGICAL    SURVEY    DIVISION 


FRANK  W.    DE  WOLF.  Ch( 


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SIUFICIAL  CiEDUHiY  AND   ROCK  OUTCROPS  OF  THE   MORRIS  QUADRANGLE 


DEPARTMENT    OF    REGISTRATION    AND     EDUCATION 

STATE    GEOLOGICAL    SURVEY    DIVISION 

N  D.  SALtSeURY,  THE   DIRECTOR  OF  REGISTRATION  AND  EDUCA 
FRANK  W,    DE  WOLF-  Chief 


ECONOMIC,  STRUCTURAL  AND  AREAL  GEOLOGY  OF  THE  MORRIS  QUADRANGLE 


UNIVERSITY  OF  ILLINOIS-URBANA 


3  0112  061867013 


